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Microscopic evaluation

If the referral does not point to any particular request (see "Most common requests" above), the following algorithm may be applied:

In intraoperative consultations by frozen section, it is generally sufficient to report clear margins if present, and specification of the type of tumor can be deferred to permanent sections.

Reporting

Preferably see specific articles from algorithm in section above.

  • Optionally, the presence of a keratinized squamous epithelium.
  • Any abnormalities, generally preceded by location in terms of epidermal, dermal or more specific layers thereof.
  • If malignant:
  • Degree of differentiation
  • Radicality/Least distance to a margin
  • Perineural or vascular invasion if present

Suspected malignant skin excisions

Author: Mikael Häggström [note 1]
Suspected malignant skin excisions:

Fixation

Generally 10% neutral buffered formalin.

  See also: General notes on fixation


Common targets

If directly suspected from the referral, see:

  • Melanoma

Gross processing

Gross examination

Note:

  • Color
  • Well-defined or diffuse border
  • Size
  • Any elevation

Tissue selection

Tissue selection from suspected malignant skin lesions, by lesion size:[1][note 2]
<4 mm 4 - 8 mm 9 - 15 mm
Tissue selection from skin excision with less than 4 mm suspected malignant lesion.png Tissue selection from skin excision with 4-8 mm suspected malignant lesion.png Tissue selection from skin excision with 9-15 mm suspected malignant lesion.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

If the lesion was pigmented on gross examination, evaluate as a dark skin focality. If not:

Look for atypical cells, possibly by scrolling through the epidermis at intermediate magnification and then through the dermis at a lower magnification. If atypical cells are found, look for:

  • Similarity to squamous cells: See below:

Squamous cell-like skin proliferations: Differential diagnosis

Main differential diagnoses and their characteristics:[2]

General benign imitators of skin malignancy

Further workup of malignant findings

In case of skin cancer, determine whether the peripheral/radial and deep margins are clear, close or continuous.[3][note 5] A close margin has various definitions for different malignancies, but for basal-cell carcinoma and cutaneous squamous cell carcinoma it is defined as being closer than 1 mm from the edge (but yet non-continuous with it),[3][4] but 2-3 mm for melanoma.[5]

Previous biopsy

(At least if there is a known previous biopsy, look for changes that are consistent with a biopsy site, to confirm that it was taken from the excised area.) Such changes in the skin include:

  • Granulation tissue in more fresh biopsies
  • Dense collagen
  • Fibrosis with vertical blood vessels
  • Fibrosis that replaces solar elastosis

Reporting

Preferably see specific article on the condition at hand, if available.

  • Optionally, the presence of a keratinized squamous epithelium.
  • Any abnormalities, generally preceded by location in terms of epidermal, dermal or more specific layers thereof.
  • If malignant:
  • Degree of differentiation
  • Radicality, mainly into either of the following: edit
  • >___ mm (Definitions vary for the distance as per Further workup of malignant findings above): "Clear margins" (or: "Clear margins at over __ mm")((or the exact distance thereof)).))
  • <___ mm but not continuous with edge: "Close margins at __ mm at (location). [[Locations are mainly the deep edge, or the (superior/inferior/medial/lateral) radial edge.]]." Numbers are generally given at an exactness of 0.1 mm.[3]
  • Continuous with margin: "Not radically excised at (location)."
  • Perineural or vascular invasion if present.

Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
  2. The excision example shows a superficial basal cell carcinoma.
  3. - Buschke–Löwenstein tumor is an alternative name for verrucous squamous cell carcinoma in the ano-genital region.
    - Carcinoma cuniculatum is a characteristic form of verrucous squamous cell carcinoma on the sole.
  4. Inverted follicular keratosis is generally thought to be a rare variant of seborrheic keratosis, but this position is not universally accepted.
    - Karadag, AyseSerap; Ozlu, Emin; Uzuncakmak, TugbaKevser; Akdeniz, Necmettin; Cobanoglu, Bengu; Oman, Berkant (2016). "Inverted follicular keratosis successfully treated with imiquimod ". Indian Dermatology Online Journal 7 (3): 177. doi:10.4103/2229-5178.182354. ISSN 2229-5178. 
  5. "Peripheral" or "radial" margins are preferred rather than "lateral", since a "lateral" margin may be interpreted as opposite to the "medial margin".

Main page

References

  1. There are many variants for the processing of skin excisions. These examples use aspects from the following sources: ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  2. Initially copied from: Paolino, Giovanni; Donati, Michele; Didona, Dario; Mercuri, Santo; Cantisani, Carmen (2017). "Histology of Non-Melanoma Skin Cancers: An Update ". Biomedicines 5 (4): 71. doi:10.3390/biomedicines5040071. ISSN 2227-9059. 
    "This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)."
  3. 3.0 3.1 3.2 David Slater, Paul Barrett. Standards and datasets for reporting cancers - Dataset for histopathological reporting of primary cutaneous basal cell carcinoma. The Royal College of Pathologists. February 2019
  4. 1 mm as cutoff for close margin: Brodie M Elliott, Benjamin R Douglass, Daniel McConnell, Blair Johnson, Christopher Harmston (2018-12-14). New Zealand Medical Journal.
  5. Page 406 in: Klaus J. Busam, Richard A Scolyer, Pedram Gerami (2018). Pathology of Melanocytic Tumors . Elsevier Health Sciences. ISBN 9780323508681. 

Image sources


Basal-cell carcinoma

Author: Mikael Häggström [note 1]

Nodular basal-cell carcinoma.

Basal-cell carcinoma (BCC):

Fixation

Generally 10% neutral buffered formalin.

  See also: General notes on fixation


Gross processing

Gross examination

Note:

  • Color
  • Well-defined or diffuse border
  • Size
  • Any elevation

Tissue selection

Tissue selection from suspected malignant skin lesions, by lesion size:[1][note 2]
<4 mm 4 - 8 mm 9 - 15 mm
Tissue selection from skin excision with less than 4 mm suspected malignant lesion.png Tissue selection from skin excision with 4-8 mm suspected malignant lesion.png Tissue selection from skin excision with 9-15 mm suspected malignant lesion.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

Broadly consists of determining the following:

  • Whether it is basal-cell carcinoma or a differential diagnosis.
  • Aggressiveness pattern
  • Radicality

Optionally, further subtyping of basal-cell carcinoma can be made.

Characteristics

Basal-cell carcinomas may be pigmented as shown (but consider the possibility of melanoma in such cases).

In uncertain cases, immunohistochemistry using BerEP4 can be used, having a high sensitivity and specificity in detecting only BCC cells.[3]

Differential diagnoses

Main histological differential diagnoses of basal cell carcinoma:

Hair follicles

The edges of hair follicle cells may resemble palisades, but are less pronounced, and are generally more diffusely delineated compared to surroundings.

Squamous-cell carcinoma

Squamous-cell carcinoma of the skin is generally distinguishable by for example relatively more cytoplasm, horn cyst formation and absence of palisading and cleft formations.

edit

Yet, a high prevalence means a relatively high incidence of borderline cases. In such cases, look particularly at the surface and attempt to classify as either of the following:

In unclear cases, the most useful immunohistochemistry marker appears to be MOC-31, which essentially always stains metatypical basal-cell carcinomas but not basaloid squamous-cell carcinomas.[5] UEA-1 appears to be the second most useful marker, staining almost all basaloid squamous-cell carcinomas but only a few metatypical basal-cell carcinomas.[5]

Others[6]

Aggressiveness

Aggressiveness can be classified as low-level aggressive, moderately aggressive and highly aggressive, based mainly the cohesion of cancer cells, but also upon other histopathologic subtypes:

Low-level aggressive patterns
Moderately aggressive pattern
Highly aggressive patterns

Radicality

Determine if there are basal-cell formations continuous with resection margins, or if they are closer or farther than 1 mm from the closest edge.[10] If closer, measure the distance.

If uncertain, immunohistochemistry with BerEP4 helps in distinguishing the BCC cells.

Comparison H&E stain (left) with BerEP4 immunohistochemistry staining (right) on a pathological section having BCC with squamous cell metaplasia. Only BCC cells are stained with BerEP4.[3]
Further information: Evaluation of tumors

Reporting

  • Aggressiveness pattern, at least if highly aggressive.
  • Radicality, mainly into either of the following: edit
  • >1 mm (as per Radicality above): "Clear margins" (or: "Clear margins at over __ mm")((or the exact distance thereof)).))
  • <1 mm but not continuous with edge: "Close margins at __ mm at (location). [[Locations are mainly the deep edge, or the (superior/inferior/medial/lateral) radial edge.]]." Numbers are generally given at an exactness of 0.1 mm.[10]
  • Continuous with margin: "Not radically excised at (location)."

Optionally, subtype of basal-cell carcinoma

Example:

Non-radical basal-cell cancer.jpg
(Skin excision with stratified squamous keratinized epithelium, where the dermis contains) moderately aggressive basal-cell carcinoma, not radically excised at the right margin.[note 4]

  See also: General notes on reporting


Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
  2. The excision example shows a superficial basal cell carcinoma.
  3. Desmoplastic tricoepithelioma is particularly similar to basal-cell carcinoma.
  4. The direction was known from needle marking.

Main page

References

  1. There are many variants for the processing of skin excisions. These examples use aspects from the following sources: ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  2. Robert S Bader. Which histologic findings are characteristic of basal cell carcinoma (BCC)?. Medscape. Updated: Feb 21, 2019
  3. 3.0 3.1 Sunjaya, Anthony Paulo; Sunjaya, Angela Felicia; Tan, Sukmawati Tansil (2017). "The Use of BEREP4 Immunohistochemistry Staining for Detection of Basal Cell Carcinoma ". Journal of Skin Cancer 2017: 1–10. doi:10.1155/2017/2692604. ISSN 2090-2905. 
  4. El-Mofty, SK. (2014). "Histopathologic risk factors in oral and oropharyngeal squamous cell carcinoma variants: An update with special reference to HPV-related carcinomas ". Medicina Oral Patología Oral y Cirugia Bucal: e377–e385. doi:10.4317/medoral.20184. ISSN 16986946. 
    License: CC BY 2.5
  5. 5.0 5.1 Webb, David V.; Mentrikoski, Mark J.; Verduin, Lindsey; Brill, Louis B.; Wick, Mark R. (2015). "Basal cell carcinoma vs basaloid squamous cell carcinoma of the skin: an immunohistochemical reappraisal ". Annals of Diagnostic Pathology 19 (2): 70–75. doi:10.1016/j.anndiagpath.2015.01.004. ISSN 10929134. 
  6. 6.0 6.1 6.2 6.3 6.4 Paolino, Giovanni; Donati, Michele; Didona, Dario; Mercuri, Santo; Cantisani, Carmen (2017). "Histology of Non-Melanoma Skin Cancers: An Update ". Biomedicines 5 (4): 71. doi:10.3390/biomedicines5040071. ISSN 2227-9059. 
  7. Inskip, Mike; Magee, Jill (2015). "Microcystic adnexal carcinoma of the cheek—a case report with dermatoscopy and dermatopathology ". Dermatology Practical & Conceptual 5 (1). doi:10.5826/dpc.0501a07. ISSN 21609381. 
  8. Yonan, Yousif; Maly, Connor; DiCaudo, David; Mangold, Aaron; Pittelkow, Mark; Swanson, David (2019). "Dermoscopic Description of Fibroepithelioma of Pinkus with Negative Network ". Dermatology Practical & Conceptual: 246–247. doi:10.5826/dpc.0903a23. ISSN 2160-9381.  Creative Commons Attribution License
  9. East, Ellen; Fullen, Douglas R.; Arps, David; Patel, Rajiv M.; Palanisamy, Nallasivam; Carskadon, Shannon; Harms, Paul W. (2016). "Morpheaform Basal Cell Carcinomas With Areas of Predominantly Single-Cell Pattern of Infiltration ". The American Journal of Dermatopathology 38 (10): 744–750. doi:10.1097/DAD.0000000000000541. ISSN 0193-1091. 
  10. 10.0 10.1 David Slater, Paul Barrett. Standards and datasets for reporting cancers - Dataset for histopathological reporting of primary cutaneous basal cell carcinoma. The Royal College of Pathologists. February 2019

Image sources


Actinic keratosis

Authors: Mikael Häggström; Authors of integrated Creative Commons article[1] [note 1]
Actinic keratosis may present as suspected malignant skin excisions.

Fixation

Generally 10% neutral buffered formalin.

  See also: General notes on fixation


Gross processing

Multiple lesions of actinic keratosis on the scalp.

Gross examination

Note:

  • Color
  • Well-defined or diffuse border
  • Size
  • Any elevation

Lesions of actinic keratosis are typically ill-marginated, erythematous, scaling, and rough papules or patches. These will typically be found in areas displaying other signs of solar damage, such as atrophy, uneven pigmentation, and telangiectasias.[1]

Tissue selection

Tissue selection from suspected malignant skin lesions, by lesion size:[2][note 2]
<4 mm 4 - 8 mm 9 - 15 mm
Tissue selection from skin excision with less than 4 mm suspected malignant lesion.png Tissue selection from skin excision with 4-8 mm suspected malignant lesion.png Tissue selection from skin excision with 9-15 mm suspected malignant lesion.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

  • Evaluation mainly consists of:

Characteristics

Normal skin (left) and actinic keratosis (right) with the defining characteristic of atypical basal keratinocytes that does not involve the full thickness of the epidermis.
1(a). Actinic keratosis at low magnification, showing discontinuous parakeratosis (as the dysplastic process spares adnexal structures, including sebaceous glands. This specimen also demonstrates dense dermal elastosis).[1]

By definition, actinic keratosis is confined to foci within the epidermis.[1]
it also generally has:[1]

  • Aggregates of atypical, pleomorphic keratinocytes which show nuclear atypia, dyskeratosis, and loss of polarity.
  • Hyperkeratosis and parakeratosis, the latter overlying the abnormal cells in the epidermis. Due to the sparing of segments of the epithelium overlying adnexal structures, a characteristic pattern of alternating orthokeratosis and parakeratosis, referred to as the “flag-sign,” can often be seen (Figure 1(a)).
  • Atypical keratinocytes will not span the full thickness of the epidermis (Figure 1(b)), although those in the basal cell layer will frequently extend into the granular and cornified layers. The exception to this criterion is the Bowenoid variant of actinic keratosis, which resembles cutaneous squamous-cell carcinoma in situ (Bowen's disease) but is less disordered with less nuclear atypia and crowding.
  • A more basophilic basal layer than normal, which is generally thought to be a consequence of the close crowding of atypical keratinocytes (Figure 1(b)).
  • Some cases will also show basal layer degeneration and the formation of Civatte bodies (Figure 1(c)), the result of a lichenoid infiltrate with irregular acanthosis. This can be distinguished from lichenoid dermatitis by the presence of keratinocyte atypia.
  • Dermoepidermal junction irregularities, with small round buds at the basal cell layer that will protrude slightly into the upper papillary dermis (Figure 1(d)).
  • There is almost always an associated solar elastosis in the dermis, and a lack thereof can often be sufficient to prompt reconsideration of the diagnosis.


Squamous cell-like skin proliferations: Differential diagnosis

Main differential diagnoses and their characteristics:[3]

Clinical clues

  • Biopsy from sun exposed area (including the face, neck, dorsal hands, and forearms, upper chest, back, and scalp).[1]
  • Generally middle-aged or older individuals.[1]

Further workup

Once a diagnosis of actinic keratosis is established, optionally characterize the degree of atypia into either mild, moderate or severe.

File:Histopathology of actinic keratosis with moderate atypia.jpg
Actinic keratosis with moderate atypia, spanning approximately half of stratum spinosum.

Histopathology report

  • Objective findings
  • A diagnosis of actinic keratosis
  • Optionally: The degree of atypia.
  • Even absence of evidence of malignancy.

Example for the case in "Further workup":

(Skin excision with squamous stratified epithelium with moderate) atypia in the basal epidermis (, with enlarged and dark cell nuclei as well as slightly disrupted cell arrangements.) No evidence of malignancy.

  See also: General notes on reporting


Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
  2. The excision example shows a superficial basal cell carcinoma.
  3. - Buschke–Löwenstein tumor is an alternative name for verrucous squamous cell carcinoma in the ano-genital region.
    - Carcinoma cuniculatum is a characteristic form of verrucous squamous cell carcinoma on the sole.
  4. Inverted follicular keratosis is generally thought to be a rare variant of seborrheic keratosis, but this position is not universally accepted.
    - Karadag, AyseSerap; Ozlu, Emin; Uzuncakmak, TugbaKevser; Akdeniz, Necmettin; Cobanoglu, Bengu; Oman, Berkant (2016). "Inverted follicular keratosis successfully treated with imiquimod ". Indian Dermatology Online Journal 7 (3): 177. doi:10.4103/2229-5178.182354. ISSN 2229-5178. 

Main page

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Initially largely copied from: Yanofsky, Valerie R.; Mercer, Stephen E.; Phelps, Robert G. (2011). "Histopathological Variants of Cutaneous Squamous Cell Carcinoma: A Review ". Journal of Skin Cancer 2011: 1–13. doi:10.1155/2011/210813. ISSN 2090-2905. 
    -"This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited."
  2. There are many variants for the processing of skin excisions. These examples use aspects from the following sources: ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  3. Initially copied from: Paolino, Giovanni; Donati, Michele; Didona, Dario; Mercuri, Santo; Cantisani, Carmen (2017). "Histology of Non-Melanoma Skin Cancers: An Update ". Biomedicines 5 (4): 71. doi:10.3390/biomedicines5040071. ISSN 2227-9059. 
    "This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)."

Image sources


Squamous-cell carcinoma of the skin

Authors: Mikael Häggström; Authors of integrated Creative Commons article[1] [note 1]
Squamous-cell carcinoma (SCC) of the skin may present as suspected malignant skin excisions.

Fixation

Generally 10% neutral buffered formalin.

  See also: General notes on fixation


Gross processing

Squamous cell carcinoma in situ.
SCC with scaling and ulceration.

If re-excision, see separate section at bottom.

Gross examination

Note:

  • Color
  • Well-defined or diffuse border
  • Size
  • Any elevation

Squamous cell carcinoma in situ (essentially synonymous with Bowen’s disease) often presents as an erythematous, well-demarcated, scaly patch or plaque, with a fairly irregular border. They occasionally present as dark skin focalities, especially when found in the genital region and the nails.[1]

Invasive SCC typically has ill-marginated, erythematous, scaling, and rough papules or patches.[1]

Tissue selection

Tissue selection from suspected malignant skin lesions, by lesion size:[2][note 2]
<4 mm 4 - 8 mm 9 - 15 mm
Tissue selection from skin excision with less than 4 mm suspected malignant lesion.png Tissue selection from skin excision with 4-8 mm suspected malignant lesion.png Tissue selection from skin excision with 9-15 mm suspected malignant lesion.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

Evaluation consists of:

  • Determining whether it is a SCC rather than a differential diagnosis.
  • Distinguishing a SCC in situ from an invasive SCC
  • Radicality, and if radical, determine the least distance to a margin.

Characteristics

Squamous cell carcinoma in situ, showing prominent dyskeratosis and aberrant mitoses at all levels of the epidermis, along with marked parakeratosis.[1]
Main characteristics of squamous-cell carcinoma regardless of location.
  • Malignant keratinocytes demonstrating intense mitotic activity, pleomorphism, and greatly enlarged nuclei. They will also show a loss of maturity and polarity, giving the epidermis a disordered or “windblown” appearance.

In situ

In SCC in situ (Bowen’s disease) the epidermis will show:

  • Atypia spanning the full thickness of the epidermis, being the main finding.[1]
  • Hyperkeratosis and parakeratosis.[1]
  • Marked acanthosis with elongation and thickening of the rete ridges. These changes will overly keratinocytic cells which are often highly atypical and may in fact have a more unusual appearance than invasive SCC.
  • Typical squamous-cell carcinoma cells are large with abundant eosinophilic cytoplasm and large, often vesicular, nuclei.[3]
  • Two types of multinucleated cells may be seen:[1]
  • Multinucleated giant cells
  • Dyskeratotic cells engulfed in the cytoplasm of keratinocytes.
  • Occasionally, cells of the upper epidermis will undergo vacuolization.[1]

There may be a mild to moderate lymphohistiocytic infiltrate detected in the upper dermis.[1]

Histopathology of squamous cell carcinoma in situ.jpg
Atypia spanning the full thickness of the epidermis is enough in this case for the diagnosis of SCC in situ. There is also a lymphohistiocytic infiltrate.

In contrast to actinic keratosis, the basal epidermal layer in SCC in situ is frequently spared, and will show little to no visible atypia. Additionally, SCC in situ will almost always involve both the interfollicular and adjacent follicular epithelium and adnexal structures.[1]

Overlap of squamous-cell and basal-cell carcinoma

Basal-cell carcinoma is generally distinguishable by for example relatively less cytoplasm, palisading, cleft formations and absence of horn cyst formation.

edit

Yet, a high prevalence means a relatively high incidence of borderline cases. In such cases, look particularly at the surface and attempt to classify as either of the following:

In unclear cases, the most useful immunohistochemistry marker appears to be MOC-31, which essentially always stains metatypical basal-cell carcinomas but not basaloid squamous-cell carcinomas.[5] UEA-1 appears to be the second most useful marker, staining almost all basaloid squamous-cell carcinomas but only a few metatypical basal-cell carcinomas.[5]

Clinical clues

  • Biopsy from sun exposed area (including the face, neck, dorsal hands, and forearms, upper chest, back, and scalp).[1]
  • Generally middle-aged or older individuals.[1]

In situ versus invasive

In situ (Bowen's disease)
Intact basement membrane.
Invasive SCC

Invasive SCC is defined by dermal infiltration.

This infiltrate can be somewhat difficult to detect in the early stages of invasion: however, additional indicators such as full thickness epidermal atypia and the involvement of hair follicles can be used to facilitate the diagnosis. Later stages of invasion are characterized by the formation of nests of atypical tumor cells in the dermis, often with a corresponding inflammatory infiltrate.[1]

Radicality

Determine whether the distances between atypical cells are more or less than 1 mm from the deep and radial edges. If less than 1 mm, quantify the distance.[6]

Degree of differentiation

Applicable to invasive SCC. edit

Perineural or vascular invasion

In SCC, look for any perineural invasion,[note 3] and at least a quick glance for any vascular invasion.

Perineural invasion is defined as tumor in close proximity to nerve and involving at least 33% of its circumference or tumor cells within any of the three layers of the nerve sheath (epineurium, perineurium and endoneurium).[7] First look along the border of the tumor, followed by surrounding tissue, and if still not found, look through the rest of the tumor area as well.[1]

Staging

The AJCC, 8th Ed., does not include any staging system for skin SCC, except for tumors of the vulva.[8]

Optionally: Grading

Multiple variables can be combined to classify a SCC as low or high grade:

Low-Grade SCC[1] High-Grade SCC[1]
  • Well to moderately differentiated: intercellular bridges and keratin pearls
  • Tumor cells arranged in solid or sheet-like patterns
  • Association with solar damage and precursor actinic keratosis
  • Diameter less than 2 cm
  • Depth less than 2 mm
  • Poorly differentiated: clear-cell, sarcomatoid, or single cell features
  • Presence of infiltrating individual tumor cells
  • Arising de novo or in site of prior injury (ulcer, burn scar, or osteomyleitis)
  • Perineural and/or perivascular invasion
  • Diameter greater than 2 cm
  • Depth greater than 2 mm

Further work-up

In vulvar squamous cell carcinoma, generally perform p16 immunohistochemistry, which is considered a surrogate marker for oncogenic HPV infection.[9]

Microscopy report

On this resource, the following formatting is used for comprehensiveness:

  • Minimal depth
  • (Moderate depth)
  • ((Comprehensive))

Components of the report:

  • Diagnosis of squamous-cell carcinoma
  • Whether it is in situ or invasive. If invasive:
  • Degree of differentiation.
  • (High or low grade.)
  • Even absence of perineural invasion[note 3]
  • ((Even absence of or vascular invasion.))
  • Radicality, mainly into either of the following: edit
  • >1 mm (as per Radicality above): "Clear margins" (or: "Clear margins at over __ mm")((or the exact distance thereof)).))
  • <1 mm but not continuous with edge: "Close margins at __ mm at (location). [[Locations are mainly the deep edge, or the (superior/inferior/medial/lateral) radial edge.]]."[6] Numbers are generally given at an exactness of 0.1 mm.
  • Continuous with margin: "Not radically excised at (location)."
  • Staging is only applicable for the head and neck (lip, ear, face, scalp and neck - see staging at Medscape) and vulva (see staging at cancer.net).

((You may also add a synoptic report (see examples):))

Examples

Squamous cell carcinoma in situ:

Micrograph of squamous cell carcinoma in situ - 100x.jpg
((Skin excision with squamous epithelium with))(central parakeratosis. The epidermis is thickened and exhibits disturbed stratification. )All cell layers show atypical epithelial cells with polymorphic and partially hyperchromatic nuclei. The basement membrane is intact. Clear margins. ((There is elastosis and inflammatory cells in the dermis.))

Invasive squamous cell carcinoma:

(Skin, right breast, excision:)
Invasive keratinizing squamous cell carcinoma, well differentiated, measuring 1.7 cm in greatest dimension.
Surgical margins are negative for carcinoma.
(Negative for lymphovascular and perineural invasion.)
((Solar elastosis.))

((Example synoptic report:))

  • Procedure: Skin excision.
  • Tumor site: Scalp
  • Tumor laterality: Right
  • Tumor focality: Unifocal
  • Tumor size: 1.6 x 1.4 cm
  • Tumor depth of invasion: 0.3 cm
  • Histologic type: Squamous cell carcinoma
  • Histologic grade: Moderately differentiated
  • Specimen margins: Uninvolved by invasive tumor.
  • Lymphovascular invasion: Not identified
  • Perineural invasion: Not identified
  • Regional lymph nodes: No lymph nodes submitted or found.
  • Pathologic Stage Classification (pTNM, AJCC 8th Edition):
  • Primary Tumor: pT1
  • Regional Lymph Nodes: pNX: Regional lymph nodes cannot be assessed
  • Additional pathologic findings: Actinic keratosis

Example microscopic description of invasive squamous cell carcinoma:

  • Squamous epithelium, with central ulceration, surrounded by hyperkeratosis. In this area in the dermis there are infiltrative nests of epithelioid cells with nuclear pleomorphism and <sparse / moderate / abundant> keratin formation.

  See also: General notes on reporting


Re-excisions

Gross processing

Tissue selection from skin re-excisions.png

edit
((Submit the entire specimen, or)) depending on radicality of previous excision:

  • Previously radical (including thin margins): Submit at least one central section across the surgical scar.[10]
  • Previously non-radical:
  • Visible lesion: Submit the entire scar.[10]
  • Lesion not visible: At least one additional radicality slice towards the tips, up to the entire specimen.[11]

Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
  2. The excision example shows a superficial basal cell carcinoma.
  3. 3.0 3.1 Presence or absence of perineural invasion in squamous-cell carcinoma affects whether adjuvant radiotherapy will be used.

Main page

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 Yanofsky, Valerie R.; Mercer, Stephen E.; Phelps, Robert G. (2011). "Histopathological Variants of Cutaneous Squamous Cell Carcinoma: A Review ". Journal of Skin Cancer 2011: 1–13. doi:10.1155/2011/210813. ISSN 2090-2905. .
    -"This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited."
  2. There are many variants for the processing of skin excisions. These examples use aspects from the following sources: ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  3. Dr Nicholas Turnbull, A/Prof Patrick Emanual (2014-05-03). Squamous cell carcinoma pathology. DermNetz.
  4. El-Mofty, SK. (2014). "Histopathologic risk factors in oral and oropharyngeal squamous cell carcinoma variants: An update with special reference to HPV-related carcinomas ". Medicina Oral Patología Oral y Cirugia Bucal: e377–e385. doi:10.4317/medoral.20184. ISSN 16986946. 
    License: CC BY 2.5
  5. 5.0 5.1 Webb, David V.; Mentrikoski, Mark J.; Verduin, Lindsey; Brill, Louis B.; Wick, Mark R. (2015). "Basal cell carcinoma vs basaloid squamous cell carcinoma of the skin: an immunohistochemical reappraisal ". Annals of Diagnostic Pathology 19 (2): 70–75. doi:10.1016/j.anndiagpath.2015.01.004. ISSN 10929134. 
  6. 6.0 6.1 1 mm as cutoff for close margin: Brodie M Elliott, Benjamin R Douglass, Daniel McConnell, Blair Johnson, Christopher Harmston (2018-12-14). New Zealand Medical Journal.
  7. Strowd, Roy (2021). Neuro-oncology for the clinical neurologist . Philadelphia, PA: Elsevier. ISBN 978-0-323-69494-0. OCLC 1220993756. 
  8. Amin, Mahul (2017). AJCC cancer staging manual (8 ed.). Switzerland: Springer. ISBN 978-3-319-40617-6. OCLC 961218414. 
    - For access, see the Secrets chapter of Patholines.
    - Copyright note: The AJCC, 8th Ed. is published by a company in Switzerland, and the tables presented therein are Public Domain because they consist of tabular information without literary or artistic innovation, and therefore do not fulfil the inclusion criterion of the Swiss Copyright Act (CopA) which applies to "literary and artistic intellectual creations with individual character" (see Federal Act on Copyright and Related Rights (Copyright Act, CopA) of 9 October 1992 (Status as of 1 January 2022)). edit
  9. Anjelica Hodgson, M.D., Carlos Parra-Herran, M.D.. p16. Pathology Outlines. Last author update: 1 July 2017. Last staff update: 20 July 2022
  10. 10.0 10.1 Katarzyna Lundmark. Handläggning av hudprover – provtagningsanvisningar, utskärningsprinciper och snittning (Handling of skin samples - sampling instructions, cutting principles and incision. Swedish Society of Pathology.
  11. Pathology Department at NU Hospital Group, Sweden, 2019-2020.

Image sources


Melanoma in situ

Author: Mikael Häggström [note 1]
Melanoma of the skin generally presents as a dark skin focality and/or a suspected malignant skin excision.

Fixation

Generally 10% neutral buffered formalin.

  See also: General notes on fixation


Gross processing

Gross examination

Note:

  • Color
  • Well-defined or diffuse border
  • Size
  • Any elevation

Tissue selection

Tissue selection from suspected malignant skin lesions, by lesion size:[1][note 2]
<4 mm 4 - 8 mm 9 - 15 mm
Tissue selection from skin excision with less than 4 mm suspected malignant lesion.png Tissue selection from skin excision with 4-8 mm suspected malignant lesion.png Tissue selection from skin excision with 9-15 mm suspected malignant lesion.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

Differential diagnoses

Distinguish mainly from dysplastic nevus and invasive melanoma of the skin:

Dysplastic nevus

Comparison of congenital pattern nevus, dysplastic nevus and suspected melanoma   edit
Parameter Non-atypical congenital pattern Low-grade dysplastic nevus High-grade dysplastic nevus Suspected melanoma in situ
Mild dysplasia Moderate dysplasia Severe dysplasia
Macroscopic Lateral circumscription[2] Sharp Slightly diminished Moderate Poor
Excised melanoma in situ.jpg
Symmetry[2] Good Often broken Rare
Structural
(Low
mag.)
Delimitation[3] Rarely diffuse Sometimes diffuse Often diffuse
Lentiginous proliferation[note 3][3] Yes, along with rete pegs Yes, along with and focally between rete pegs Yes, along with and focally between rete pegs Yes partially continuous, multilayered
Histopathology of lentigo maligna.jpg
Bridging[3] Rarely Often
Confluent nests[3] Rarely Sometimes Often Often widespread
Pigment distribution[3] Regular Irregular
Suprabasal presence (less than most superficial third of subcorneal epidermis) Occasionally centrally[2] No[3] or rarely[2] Occasionally centrally[2] Yes, multifocal[3]
Pagetoid migration including superficial third of subcorneal epidermis[3] No No Yes, in a maximum of 2 HPF centrally, but not peripherally Yes, multifocal and/or in periphery
Peripheral.
Extended rete pegs Ocassional[2] Yes, regular[3] Yes, varying[3] Yes, often irregular[3] Varying, flattened[3]
Concentric fibrosis Regressive[2] Yes[3] Occasional[2]
Lamellar fibrosis Rarely[3] Often[3] Often pronounced[3] Occasional[2]
Lymphocytic infiltrate[3] Mild, perivascular Mild or moderate, perivascular Varying Varying
Suprapapillary plate involvement No[2] Usually no[2] Often[2] Yes[2]
Cellular
(high
mag.)
Image Compound nevus with moderate atypia.jpg
Junctional extension[2] Unusual Usual Extensive
Nuclear size[2] Age-related Small Medium Large Medium or large. Pleomorphic[4]
Nuclear pleomorphism[5] Slight Prominent
Chromatin pattern Uniform[2] Condensed[2] Partically expanded[2] Expanded, coarse in some cells[2] Expanded, hyperchromatic, coarse.[2] Usually granular.[5]
Nucleoli[2] Age-related Small Medium Large Usually[5] large
Mitoses[2] Few superficial Superficial and deep
Histological regression[5][note 4] Usually Usually not
Percentage of atypical melanocytes[3] <10% About 10 - 50% about 50-90% Usually> 90%
Intradermal melanocytic atypia[3] No Rarely, in superficial part Can be detected in superficial part
Intradermal melanocyte maturation[3] Yes Yes, can be partial Yes, can be partial Variable

In suspected but not certain nevus or melanoma in situ, generally perform immunohistochemistry with SOX10, whereby melanocyte proliferation and nuclear pleomorphism is easier to see.[note 5]

Further information: Evaluation of suspected malignancies

Invasive melanoma of the skin

Invasive melanoma of the skin has features melanoma in situ, but also has dermal involvement of atypical melanocytes with cytologic atypia and no maturation.[6]

Further workup

Upon a diagnosis of melanoma in situ, evaluate its margins.
Optionally, attempt to determine the histopathologic type and amount of cytoplasmic pigmentation:

Margins

If melanoma, determine if the distance to any margin is greater or lesser than 2-3 mm.

  • 2 mm is used as a cutoff for sharply demarcated, small, superficially spreading or nevoid melanomas.[7]
  • 3 mm is used for ill-defined lentigo maligna melanoma in situ.[7]

If lesser, quantify the distance.

If margins are difficult to determine, consider immunohistochemistry with SOX10 to better visualize melanoma nests.[note 5]

Histopathologic type

Main types of melanoma in situ are:

Type Features Micrograph
Superficial spreading melanoma in situ Melanoma cells with nest formation along the dermo-epidermal junction. File:Histopathology of superficial spreading melanoma.jpg
Lentigo maligna Linear spread of atypical epidermal melanocytes along stratum basale.[8]
Histopathology of lentigo maligna.jpg
Acral lentiginous melanoma in situ Continuous proliferation of atypical melanocytes at the dermoepidermal junction.[9] Histopathology of acral lentiginous melanoma in situ, intermediate magnification.jpg

Report

Most important entries:

  • Melanoma area dimensions (width x width)[10]
  • Radicality,[10] mainly into either of the following: edit
  • >2 or 3 mm (as per Further workup above): "Clear margins" (or: "Clear margins at over __ mm")((or the exact distance thereof)).))
  • <2 or 3 mm but not continuous with edge: "Close margins at __ mm at (location). [[Locations are mainly the deep edge, or the (superior/inferior/medial/lateral) radial edge.]]." Numbers are generally given at an exactness of 0.1 mm.
  • Continuous with margin: "Not radically excised at (location)."

  See also: General notes on reporting


Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
  2. The excision example shows a superficial basal cell carcinoma.
  3. Lentiginous proliferation is proliferation along the basal layer of the epidermis
  4. Histological regression is one or more areas within a tumor in which neoplastic cells have disappeared or decreased in number. In this case, this means complete or partial disappearance from areas of the dermis (and occasionally from the epidermis), which have been replaced by fibrosis, accompanied by melanophages, new blood vessels, and a variable degree of inflammation.
    - Ribero, Simone; Gualano, Maria Rosaria; Osella-Abate, Simona; Scaioli, Giacomo; Bert, Fabrizio; Sanlorenzo, Martina; Balagna, Elena; Fierro, Maria Teresa; et al. (2015). "Association of Histologic Regression in Primary Melanoma With Sentinel Lymph Node Status ". JAMA Dermatology 151 (12): 1301. doi:10.1001/jamadermatol.2015.2235. ISSN 2168-6068. 
  5. 5.0 5.1 SOX10 stains cell nuclei of melanocytes.
    - Miettinen, Markku; McCue, Peter A.; Sarlomo-Rikala, Maarit; Biernat, Wojciech; Czapiewski, Piotr; Kopczynski, Janusz; Thompson, Lester D.; Lasota, Jerzy; et al. (2015). "Sox10—A Marker for Not Only Schwannian and Melanocytic Neoplasms But Also Myoepithelial Cell Tumors of Soft Tissue ". The American Journal of Surgical Pathology 39 (6): 826–835. doi:10.1097/PAS.0000000000000398. ISSN 0147-5185. 

Main page

References

  1. There are many variants for the processing of skin excisions. These examples use aspects from the following sources: ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 Arumi-Uria, Montserrat; McNutt, N Scott; Finnerty, Bridget (2003). "Grading of Atypia in Nevi: Correlation with Melanoma Risk ". Modern Pathology 16 (8): 764–771. doi:10.1097/01.MP.0000082394.91761.E5. ISSN 0893-3952. 
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 Katarzyna Lundmark, Britta Krynitz, Ismini Vassilaki, Lena Mölne, Annika Ternesten Bratel. Histopatologisk bedömning och gradering av dysplastiskt nevus samt gränsdragning mot melanom in situ/melanom (Histopathological assessment and grading of dysplastic nevus and distinction from melanoma in situ/melanoma). KVAST (Swedish Society of Pathology). Retrieved on 2019-09-18.
  4. Christopher S. Hale. Skin melanocytic tumor - Melanoma - Invasive melanoma. Topic Completed: 1 May 2013. Revised: 17 September 2019
  5. 5.0 5.1 5.2 5.3 Husain, Ehab A; Mein, Charles; Pozo, Lucia; Blanes, Alfredo; Diaz-Cano, Salvador J (2011). "Heterogeneous topographic profiles of kinetic and cell cycle regulator microsatellites in atypical (dysplastic) melanocytic nevi ". Modern Pathology 24 (4): 471–486. doi:10.1038/modpathol.2010.143. ISSN 0893-3952. 
  6. Christopher S. Hale. Skin melanocytic tumor - Melanoma - Invasive melanoma. Pathology Outlines. Topic Completed: 1 May 2013. Revised: 17 September 2019
  7. 7.0 7.1 Measurements used to classify a melanoma as radical: Page 406 in: Klaus J. Busam, Richard A Scolyer, Pedram Gerami (2018). Pathology of Melanocytic Tumors . Elsevier Health Sciences. ISBN 9780323508681. 
  8. Error on call to Template:cite web: Parameters url and title must be specifiedHon A/Prof Amanda Oakley (2011). . DermNet NZ.
  9. Piliang, Melissa Peck (2009). "Acral Lentiginous Melanoma ". Surgical Pathology Clinics 2 (3): 535–541. doi:10.1016/j.path.2009.08.005. ISSN 18759181. 
  10. 10.0 10.1 . An Example of a Melanoma Pathology Report. Melanoma Foundation. Retrieved on 2019-09-24.

Image sources


Invasive melanoma of the skin

Author: Mikael Häggström [note 1]
Melanoma of the skin generally presents as a dark skin focality.

Fixation

Generally 10% neutral buffered formalin.

  See also: General notes on fixation


Gross processing

Gross examination

Note:

  • Color
  • Well-defined or diffuse border
  • Size
  • Any elevation

Tissue selection

Tissue selection from suspected malignant skin lesions, by lesion size:[1][note 2]
<4 mm 4 - 8 mm 9 - 15 mm
Tissue selection from skin excision with less than 4 mm suspected malignant lesion.png Tissue selection from skin excision with 4-8 mm suspected malignant lesion.png Tissue selection from skin excision with 9-15 mm suspected malignant lesion.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

Differential diagnoses

Dermal nevus

Comparison of dermal nevus and suspected invasive melanoma   edit
Parameter Non-dysplastic dermal nevus Low-grade dysplastic dermal nevus High-grade dysplastic dermal nevus Suspected invasive melanoma
Mild dysplasia Moderate dysplasia Severe dysplasia
Macroscopic Lateral circumscription[3] Sharp Slightly diminished Moderate Poor
Excised melanoma in situ.jpg
Symmetry[3] Good Often broken Rare
Structural
(Low
mag.)
Micrograph Histopathology of non-dysplastic dermal nevus, low magnification.jpg Histopathology of invasive acral lentiginous melanoma.jpg
Delimitation[4] Rarely diffuse Sometimes diffuse Often diffuse
Confluent nests[4] Rarely Sometimes Often Often widespread
Pigment distribution[4] Regular Irregular
Concentric fibrosis Regressive (see below table)[3] Yes[4] Occasional[3]
Lamellar fibrosis Rarely[4] Often[4] Often pronounced[4] Occasional[3]
Lymphocytic infiltrate[4] Mild, perivascular Mild or moderate, perivascular Varying Varying
Cellular
(high
mag.)
Micrographs Histopathology of dermal nevus, high magnification.jpg Histopathology of invasive melanoma, high magnification.jpg
Nuclear size[3] Small Medium Large Medium or large. Pleomorphic[5]
Nuclear pleomorphism[6] Slight superficial Slight Prominent
Chromatin pattern Uniform[3] Condensed[3] Partically expanded[3] Expanded, coarse in some cells[3] Expanded, hyperchromatic, coarse.[3] Usually granular.[6]
Nucleoli[3] Small Medium Large Usually[6] large
Mitoses[3] Few superficial Superficial and deep
Histological regression[6] (see below table) Usually Usually not
Percentage of atypical melanocytes[4] <10% About 10 - 50% about 50-90% Usually> 90%

Histological regression is one or more areas within a tumor in which neoplastic cells have disappeared or decreased in number. In this case, it means complete or partial disappearance of neoplastic cells from areas of the dermis (and occasionally from the epidermis), which have been replaced by fibrosis, accompanied by melanophages, new blood vessels, and a variable degree of inflammation.[7]

In suspected but not certain nevus or melanoma, generally perform immunohistochemistry with SOX10 (which stains cell nuclei of melanocytes), whereby melanocyte proliferation and nuclear pleomorphism is easier to see:[8]


Further workup

In case a diagnosis of invasive melanoma of the skin can be made, the following are generally mandatory:

  • Margins
  • Depth
  • Any ulceration
  • Histopathologic type.[9]
  • Presence of mitoses in the intradermal component.[9]

The following aspects are mandatory in some regions:

  • Clark's level (not mandatory in the US)[note 3]

Margins

Determine if the distance to any margin is greater or lesser than 3 mm.[10] If a margin is closer, measure it at an exactness of 0.1 mm.

If margins are difficult to determine, consider immunohistochemistry with SOX10 (staining the nuclei of melanocytes), to better visualize melanoma nests.[11]

Depth and ulceration

For invasive melanoma, measure the depth and whether there is ulceration or not, so as to be able to classify the T stage (following table by AJCC, 8th edition):[12]

T Category Thickness Ulceration status
TX: primary tumor
thickness cannot be
assessed (e.g., diagnosis
by curettage)
Not applicable Not applicable
T0: no evidence of
primary tumor (e.g.,
unknown primary or
completely regressed
melanoma)
Not applicable Not applicable
Tis (melanoma in situ) Not applicable Not applicable
T1 ≤1.0 mm Unknown or unspecified
T1a <0.8 mm Without ulceration
T1b <0.8 mm With ulceration
0.8–1.0 mm With or without ulceration
T2 >1.0–2.0 mm Unknown or unspecified
T2a >1.0–2.0 mm Without ulceration
T2b >1.0–2.0 mm With ulceration
T3 >2.0‐4.0 mm Unknown or unspecified
T3a >2.0–4.0 mm Without ulceration
T3b >2.0–4.0 mm With ulceration
T4 >4.0 mm Unknown or unspecified
T4a >4.0 mm Without ulceration
T4b >4.0 mm With ulceration

Histopathologic type

If needing to evaluate, the main types of invasive melanoma are:[13]

Type Features Relative incidence
(in comparison to all melanomas)[13]
Photograph Micrograph
Superficial spreading melanoma Melanoma cells with nest formation along the dermo-epidermal junction. 70% Superficial spreading melanoma in situ on dermoscopy.jpg File:Histopathology of superficial spreading melanoma.jpg
Nodular melanoma Grows relatively more in depth than in width. 15% - 20% Photography of nodular melanoma.jpg Histopathology of nodular melanoma.jpg
Lentigo maligna melanoma Atypical epidermal melanocytes as well as invasion into the dermis.[14] 5% - 10% Photograph of lentigo maligna melanoma.jpg Histopathology of lentigo maligna melanoma.jpg
Acral lentiginous melanoma Continuous proliferation of atypical melanocytes at the dermoepidermal junction.[15] 7% - 10% Photography of a large acral lentiginous melanoma.jpg Histopathology of invasive acral lentiginous melanoma.jpg

Clark's level

Skin layers.

If needing to evaluate,[note 3] Clark's levels are:[16]

  • Level 1: Melanoma confined to the epidermis (melanoma in situ)
  • Level 2: Invasion into the papillary dermis
  • Level 3: Invasion to the junction of the papillary and reticular dermis
  • Level 4: Invasion into the reticular dermis
  • Level 5: Invasion into subcutaneous tissue.

Tumor‐infiltrating Lymphocytes (TILs)

Classify as either of the following:[12]

  • Absent TIL infiltrate: no lymphocytes present or, if present, they do not interact with tumor cells.
  • Non-brisk TIL infiltrate: focal areas of lymphocytic infiltration in the tumor.
  • Brisk TIL infiltrate: TIL infiltration of the entire base of the tumor, or diffuse permeation of the tumor.

Lymph nodes

Cells that stain for melan-A but are nevus-like may be a capsular nevus

If negative on H&E stain, generally use immunohistochemistry for melanoma markers (such as a combination of melan-A and HMB-45) to exclude micrometastasis:

Other parameters

Optionally, the following parameters can be given:[17]

  • histological regression, with complete or partial disappearance from areas of the dermis (and occasionally from the epidermis), which have been replaced by fibrosis, accompanied by melanophages, new blood vessels, and a variable degree of inflammation.[18]
Further information: Evaluation of tumors

Report

Report when evaluated (as per mandatory vs. optional in Further workup above):

  • Melanoma area dimensions (width x width)[19]
  • Radicality,[19] mainly into either of the following: edit
  • >3 mm : "Clear margins" (or: "Clear margins at over __ mm")((or the exact distance thereof)).))
  • <3 mm but not continuous with edge: "Close margins at __ mm at (location). [[Locations are mainly the deep edge, or the (superior/inferior/medial/lateral) radial edge.]]." Numbers are generally given at an exactness of 0.1 mm.
  • Continuous with margin: "Not radically excised at (location)."
  • Depth or most distant invasion of melanoma cells.[19]
  • Ulceration or not, and maximum dimension if present
  • Stage as per AJCC
  • Clark's level
  • Histopathologic type
  • Mitotic rate, as amount per mm2
  • Significant signs of regression
  • Cytoplasmic pigmentation
  • Melanoma cell shapes

US example

Skin, mid upper back, excision:

  • Malignant melanoma, nodular type, Clark level IV, Breslow thickness 10mm. Surgical margins are negative for melanoma.

See synoptic report.

SYNOPTIC REPORT:

Specimen

Procedure:  Excision

Specimen Laterality:  Midline

Tumor

Tumor Site:  Skin of trunk

Histologic Type:  Nodular melanoma

Maximum Tumor (Breslow) Thickness (Millimeters): 10 mm

Macroscopic Satellite Nodule(s): Not identified

Ulceration: Present

Extent of Ulceration (Millimeters):  12 mm

Anatomic (Clark) Level: IV (Melanoma invades reticular dermis)

Mitotic Rate:  18 mitoses / mm2

Microsatellite(s):  Not identified

Lymphovascular Invasion:  Not identified

Neurotropism:  Not identified

Tumor-Infiltrating Lymphocytes:  Present, nonbrisk

Tumor Regression:  Not identified

Margins

Peripheral Margins:  Negative for invasive melanoma

Distance of Invasive Melanoma from Closest Peripheral Margin (Millimeters):  5 mm

Location:  3 o'clock and 9 o'clock

Status of melanoma in situ at peripheral margins: Negative for melanoma in situ

Distance of melanoma in situ from closest peripheral margin (millimeters):  Cannot be determined - Ulcerated surface and no in-situ noted in the remaining surface

Location:  Lateral

Deep Margin:  Negative for invasive melanoma

Distance of Invasive Melanoma from Deep Margin (Millimeters):  2 mm

Status of Melanoma in situ at Deep Margin: Negative for melanoma in situ

Distance of Melanoma in situ from Deep Margin (Millimeters):  Cannot be determined (negative for melanoma in situ)

Lymph Nodes

Regional Lymph Nodes:  No lymph nodes submitted or found

Pathologic Stage Classification (pTNM, AJCC 8th Edition)

Primary Tumor (pT):  pT4b

Regional Lymph Nodes (pN):  pNX

European example

Sun-damaged skin with central diffusely delimited proliferation of melanocytic cells having polymorphic cell nuclei, distinct nucleoli and uneven light brown pigmentation. An area of pagetoid migration is seen. There is ulceration of a smaller area. The radial margin is over 3.0 mm and the deep margin is 2.0 mm.

  • Free margin: Yes
  • Margin in mm: 2.0 mm
  • Tumor depth: 1.2 mm
  • Ulceration: Yes
  • Stage: T2b
  • Clark's level: IV
  • Histopathologic type: Superficial spreading melanoma
  • Presence of mitoses: Yes
  • Significant signs of regression: No

  See also: General notes on reporting


Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
  2. The excision example shows a superficial basal cell carcinoma.
  3. 3.0 3.1 Clark's level is not included in United States AJCC guidelines, but is mandatory for melanomas in Sweden.
    -. Breslow Depth and Clark Level. Melanoma Research Alliance. Retrieved on 2020-02-13.
    - . Bilaga 6. Kvalitetsbilaga för patologi (KVAST-bilaga). Regionala Cancercentrum i Samverkan, guidelines by Swedish Society of Pathology. Retrieved on 2020-02-13.

Main page

References

  1. There are many variants for the processing of skin excisions. These examples use aspects from the following sources: ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  2. . Melanoma in situ (stage 0). Cancer Research UK. Last reviewed: 27 Jun 2019
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 Arumi-Uria, Montserrat; McNutt, N Scott; Finnerty, Bridget (2003). "Grading of Atypia in Nevi: Correlation with Melanoma Risk ". Modern Pathology 16 (8): 764–771. doi:10.1097/01.MP.0000082394.91761.E5. ISSN 0893-3952. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Katarzyna Lundmark, Britta Krynitz, Ismini Vassilaki, Lena Mölne, Annika Ternesten Bratel. Histopatologisk bedömning och gradering av dysplastiskt nevus samt gränsdragning mot melanom in situ/melanom (Histopathological assessment and grading of dysplastic nevus and distinction from melanoma in situ/melanoma). KVAST (Swedish Society of Pathology). Retrieved on 2019-09-18.
  5. Christopher S. Hale. Skin melanocytic tumor - Melanoma - Invasive melanoma. Topic Completed: 1 May 2013. Revised: 17 September 2019
  6. 6.0 6.1 6.2 6.3 Husain, Ehab A; Mein, Charles; Pozo, Lucia; Blanes, Alfredo; Diaz-Cano, Salvador J (2011). "Heterogeneous topographic profiles of kinetic and cell cycle regulator microsatellites in atypical (dysplastic) melanocytic nevi ". Modern Pathology 24 (4): 471–486. doi:10.1038/modpathol.2010.143. ISSN 0893-3952. 
  7. Ribero, Simone; Gualano, Maria Rosaria; Osella-Abate, Simona; Scaioli, Giacomo; Bert, Fabrizio; Sanlorenzo, Martina; Balagna, Elena; Fierro, Maria Teresa; et al. (2015). "Association of Histologic Regression in Primary Melanoma With Sentinel Lymph Node Status ". JAMA Dermatology 151 (12): 1301. doi:10.1001/jamadermatol.2015.2235. ISSN 2168-6068. 
  8. Miettinen, Markku; McCue, Peter A.; Sarlomo-Rikala, Maarit; Biernat, Wojciech; Czapiewski, Piotr; Kopczynski, Janusz; Thompson, Lester D.; Lasota, Jerzy; et al. (2015). "Sox10—A Marker for Not Only Schwannian and Melanocytic Neoplasms But Also Myoepithelial Cell Tumors of Soft Tissue ". The American Journal of Surgical Pathology 39 (6): 826–835. doi:10.1097/PAS.0000000000000398. ISSN 0147-5185. 
  9. 9.0 9.1 - USA: . [https://documents.cap.org/protocols/Skin.Melanoma_4.3.0.2.REL_CAPCP.pdf Protocol for the Examination of Excision Specimens From Patients With Melanoma of the Skin]. COllege of American Pathologists. Version: 4.3.0.2. Protocol Posting Date: November 2021
    -Sweden: . Bilaga 6. Kvalitetsbilaga för patologi (KVAST-bilaga). Regionala Cancercentrum i Samverkan, guidelines by Swedish Society of Pathology. Retrieved on 2020-02-13.
  10. Definition of "thin margin": Wolf, Y.; Balicer, R.D.; Amir, A.; Feinmesser, M.; Hauben, D.J. (2001). "The vertical dimension in the surgical treatment of cutaneous malignant melanoma – how deep is deep? ". European Journal of Plastic Surgery 24 (2): 74–77. doi:10.1007/s002380100225. ISSN 0930-343X. 
  11. Miettinen, Markku; McCue, Peter A.; Sarlomo-Rikala, Maarit; Biernat, Wojciech; Czapiewski, Piotr; Kopczynski, Janusz; Thompson, Lester D.; Lasota, Jerzy; et al. (2015). "Sox10—A Marker for Not Only Schwannian and Melanocytic Neoplasms But Also Myoepithelial Cell Tumors of Soft Tissue ". The American Journal of Surgical Pathology 39 (6): 826–835. doi:10.1097/PAS.0000000000000398. ISSN 0147-5185. 
  12. 12.0 12.1 Amin, Mahul (2017). AJCC cancer staging manual (8 ed.). Switzerland: Springer. ISBN 978-3-319-40617-6. OCLC 961218414. 
    - For access, see the Secrets chapter of Patholines.
    - Copyright note: The AJCC, 8th Ed. is published by a company in Switzerland, and the tables presented therein are Public Domain because they consist of tabular information without literary or artistic innovation, and therefore do not fulfil the inclusion criterion of the Swiss Copyright Act (CopA) which applies to "literary and artistic intellectual creations with individual character" (see Federal Act on Copyright and Related Rights (Copyright Act, CopA) of 9 October 1992 (Status as of 1 January 2022)). edit
  13. 13.0 13.1 [https://books.google.se/books?id=wGclDwAAQBAJ&pg=PA805 Page 805 in: Ferri, Fred (2019). Ferri's clinical advisor 2019 : 5 books in 1 . Philadelphia, PA: Elsevier. ISBN 978-0-323-52957-0. OCLC 1040695302. 
  14. Michael Xiong; Ahmad Charifa; Chih Shan J. Chen.. Cancer, Lentigo Maligna Melanoma. StatPearls, National Center for Biotechnology Information. Last Update: May 18, 2019.
  15. Piliang, Melissa Peck (2009). "Acral Lentiginous Melanoma ". Surgical Pathology Clinics 2 (3): 535–541. doi:10.1016/j.path.2009.08.005. ISSN 18759181. 
  16. . NCI Dictionary of Cancer Terms. National Cancer Institute. Retrieved on 2020-02-13.
  17. Rees, Jonathan; Viros, Amaya; Fridlyand, Jane; Bauer, Juergen; Lasithiotakis, Konstantin; Garbe, Claus; Pinkel, Daniel; Bastian, Boris C (2008). "Improving Melanoma Classification by Integrating Genetic and Morphologic Features ". PLoS Medicine 5 (6): e120. doi:10.1371/journal.pmed.0050120. ISSN 1549-1676. 
  18. Ribero, Simone; Gualano, Maria Rosaria; Osella-Abate, Simona; Scaioli, Giacomo; Bert, Fabrizio; Sanlorenzo, Martina; Balagna, Elena; Fierro, Maria Teresa; et al. (2015). "Association of Histologic Regression in Primary Melanoma With Sentinel Lymph Node Status ". JAMA Dermatology 151 (12): 1301. doi:10.1001/jamadermatol.2015.2235. ISSN 2168-6068. 
  19. 19.0 19.1 19.2 . An Example of a Melanoma Pathology Report. Melanoma Foundation. Retrieved on 2019-09-24.

Image sources


Dermatitis

Author: Mikael Häggström [note 1]
Scope: This article deals with skin conditions where inflammation is the main finding, excluding suspected malignant skin excisions (where inflammation is often a concurrent finding).

Sampling

  • For punch biopsies, a size of 4 mm is preferred for most inflammatory dermatoses.[1]
  • Panniculitis or cutaneous lymphoproliferative disorders: 6 mm punch biopsy or skin excision.[1]

A superficial or shave biopsy is regarded as insufficient.[1]

Fixation

Generally 10% neutral buffered formalin.

  See also: General notes on fixation


Gross processing

Gross pathology processing of skin lesions with benign appearance, by lesion size:[4]
<4 mm 4 - 8 mm 9 - 15 mm

Tissue selection from skin excision with lesion less than 4 mm with benign appearance.png

Tissue selection from skin excision with lesion 4-8 mm with benign appearance.png

Tissue selection from skin excision with lesion 9-15 mm with benign appearance.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Staining

3 H&E sections and one section with periodic acid Schiff (PAS)[note 2][1]

  • If suspected bacterial and fungal microorganisms, consider Gram stain and Gomori methenamine silver stain.[1]

Microscopic evaluation

One approach is to classify into mainly either of the following, primarily based on depth of involvement:[1]

  • Epidermis, papillary dermis, and superficial vascular plexus:
  • Vesiculobullous lesions
  • Pustular dermatosis
  • Non vesicullobullous, non-pustular
  • With epidermal changes
  • Without epidermal changes. These characteristically have a superficial perivascular inflammatory infiltrate, and can be classified by type of cell infiltrate:[1]
  • Lymphocytic (most common)
  • Lymphoeosinophilic
  • Lymphoplasmacytic
  • Mast cell
  • Lymphohistiocytic
  • Neutrophilic
  • No visible pathology

Continue in corresponding section:

Non vesicullobullous, non-pustular lesions with epidermal changes

Spongiotic dermatitis

It is characterized by epithelial intercellular edema.[1]

Characteristics Micrograph Photograph
Acute Subacute Chronic
Generally/Not otherwise specified[note 3] Typical findings:[1]
  • Variable degree of epidermal spongiosis and vesicle formation, filled with proteinaceous fluid containing lymphocytes and histiocytes.
  • Usually superficial dermal edema with perivascular lymphocytic infiltrate, with exocytosis.
  • No acanthosis or parakeratosis.
Typical findings:[1]
  • Mild to moderate spongiosis and exocytosis of inflammatory cells
  • Irregular acanthosis and parakeratosis.
  • Superficial dermal perivascular lymphohistiocytic infiltrate
  • Swelling of endothelial cells
  • Papillary dermal edema are present
Typical findings:[1]
  • The spongiosis is mild to absent
  • Pronounced irregular acanthosis, hyperkeratosis, and parakeratosis
  • Minimal dermal inflammation and exocytosis of inflammatory cells are present.
  • Possibly fibrosis of papillary dermis

PAS stain is essential to exclude fungal infection.[1]

Micrograph of subacute spongiotic dermatitis.jpg Subacute
Allergic/contact dermatitis or atopic dermatitis As above. Eosinophils may be present in the dermis and epidermis (eosinophilic spongiosis).[1] Spongiotic dermatitis from drug allergy.jpg Allergic dermatitis Eczema (14100950936).jpg Atopic dermatitis
Seborrheic dermatitis Typical findings:[5]
  • Focal, usually mild, spongiosis with overlying scale crust, with a few neutrophils
  • The crust is often centered on a follicle
  • The papillary dermis is generally mildly edematous
  • Dilated blood vessels in the superficial vascular plexus
  • Mild superficial perivascular infiltrate of lymphocytes, histiocytes and occasional neutrophils. There is some exocytosis of inflammatory cells but not as prominent as in nummular dermatitis
Typical findings:[5]
  • Psoriasiform hyperplasia, initially slight, with mild spongiosis
  • Usually numerous yeast-like organisms in the surface keratin
  • Same changes as seen in acute stage.
Typical findings:[5]
  • More pronounced psoriasiform hyperplasia
  • Only minimal spongiosis
  • Presence of scaling crusts in a folliculocentric distribution, distinguishes from psoriasis.
Seborrhoeic dermatitis example.jpg

In addition to above, an unspecific spongiotic dermatitis can be consistent with nummular dermatitis, dyshidrotic dermatitis, Id reaction, dermatophytosis, miliaria, Gianotti-Crosti syndrome and pityriasis rosea.[1][note 3]

Interface dermatitis

These are sorted into either:[1]

  • Interface dermatitis with vacuolar change
  • Interface dermatitis with lichenoid inflammation
Interface dermatitis with vacuolar change
Causes of vacuolar interface dermatitis edit
Main conditions[6] Characteristics Micrograph Photograph
Generally/Not otherwise specified Typical findings, called "vacuolar interface dermatitis":[6]
  • Mild inflammatory cell infiltrate along the dermoepidermal junction (black arrow in image)
  • Vacuolization within the basal keratinocytes (white arrow in image)
  • Often necrotic, predominantly basal, individual keratinocytes, manifesting as colloid or Civatte bodies
Vacuolar interface dermatitis, annotated.jpg
Acute graft-versus-host-disease
  • Vacuolar alteration of various severity, from focal or diffuse vacuolation of the basal keratinocytes (grade I), to separation at the dermoepidermal junction (grade III)
  • Involvement of the hair follicle[6]
  • Rarely eosinophils[6]
Micrographs of grades of skin graft-versus-host-disease.jpg
Allergic drug reaction
  • Rarely involvement of hair follicles.[6]
  • Frequently eosinophils[6]
Spongiotic dermatitis from drug allergy.jpg
Lichen sclerosus Hyperkeratosis, atrophic epidermis, sclerosis of dermis and dermal lymphocytes.[7] Micrograph of lichen sclerosus.jpg
Erythema multiforme
Lupus erythematosis Typical findings in systemic lupus erythematosus:[8]
  • Fibrinoid necrosis at the dermoepidermal junction
  • Liquefactive degeneration and atrophy of the epidermis
  • Mucin deposition in the reticular dermis
  • Edema, small hemorrhages
  • Mild and mainly lymphocytic infiltrate in the upper dermis
  • Fibrinoid material in the dermis around capillary blood vessels, on collagen and in the interstitium
  • In non-bullous cases, perivascular and interstitial neutrophils are sometimes present in the upper dermis, with damage to blood vessels
Histopathology of systemic lupus erythematosus.jpg Butterfly rash of lupus erythematosus.jpg

An interface dermatitis with vacuolar alteration, not otherwise specified, may be caused by viral exanthems, phototoxic dermatitis, acute radiation dermatitis, erythema dyschromicum perstans, lupus erythematosus and dermatomyositis.[1]

Further information: Vacuolar interface dermatitis

Interface dermatitis with lichenoid inflammation
Main conditions[1] Characteristics Micrograph Photograph
Generally/Not otherwise specified Typical findings:[1]
  • In the papillary dermis: a confluent, band-like, dense inflammation of mainly small lymphocytes and a few histiocytes, along or hugging the dermoepidermal junction.
  • Often vacuolar degeneration of basal keratinocytes and apoptotic bodies (colloid or Civatte bodies).
Lichen planus Irregular epidermal hyperplasia with a jagged “sawtooth” appearance, compact hyperkeratosis or orthokeratosis, foci of wedge-shaped hypergranulosis, basilar vacuolar degeneration, slight spongiosis in the spinous layer, and squamatization. The dermal papillae between the elongated rete ridges are frequently dome shaped. Necrotic keratinocytes can be observed in the basal layer of the epidermis and at the dermal-epidermal junction. Eosinophilic remnants of anucleate apoptotic basal cells may also be found in the dermis and are referred to as “colloid or civatte bodies”. Whickham striae are usually seen in the areas of hypergranulosis. Vacuolar degeneration at the basal layer may be noted leading to focal subepidermal clefts (Max Joseph spaces). Squamatization occurs as a result of maturation and flattening of cells in the basal layer. It happens in areas of marked hypergranulosis with prominence of the sawtooth pattern of rete ridges. Wedge-shaped hypergranulosis can occur in the eccrine ducts (acrosyringia) or hair follicles (acrotrichia). In the hypertrophic subtype, the associated hyperkeratosis, parakeratosis, hypergranulosis, papillomatosis, acanthosis, and hyperplasia markedly increased with thicker collagen bundles forming in the dermis. Moreover, the rete ridges are more elongated and rounded as opposed to the typical sawtooth pattern. In atrophic LP, loss of the rete ridges and dermal fibrosis is prominent. In vesiculobullous LP, the disease progression is quicker. Hence, some of the distinctive features such as hyperkeratosis, hypergranulosis, or dense lymphocytic dermal-epidermal infiltrate may not be present. LP lesion may resolve with residual hyperpigmentation caused by a persistent increase in the number of melanophages in the papillary dermis.[9] Histopathology of lichen planus.jpg Lichen planus 1.jpg
Lichenoid drug reaction

Can virtually be indistinguishable from cutaneous LP both clinically and histopathologically.

  • Typically, lesions have a photodistribution in the absence of oral mucosal involvement.[9]
  • Characteristically parakeratosis, a dermal eosinophilic infiltrate, and a perivascular lymphocytic infiltrate affecting the reticular dermis.
  • Epidermal changes are less common in lichenoid drug eruptions when compared to classic lichen planus. However, a higher concentration of necrotic keratinocyte and eosinophils in the infiltrate can be helpful in distinguishing lichenoid drug reaction from cutaneous lichen planus. A lengthy interval between the commencement of drug therapy and the onset of lesions does not exclude a diagnosis of lichenoid drug reaction. Resolution of the lesions often occurs within weeks to months after discontinuation of the offending drug.[9]
Histopathology of lichenoid drug reaction.jpg
Lichen nitidus
  • Localized granulomatous lymphohistiocytic infiltrate in an expanded dermal papilla.
  • Thinning of overlying epidermis and downward extension of the rete ridges at the lateral margin of the infiltrate, resulting in a typical "claw clutching a ball" appearance.[10]
Histopathology of lichen nitidus.jpg Photography of lichen nitidus.jpg
Lichen amyloidosus Presence of amyloid, possibly with direct immunofluorescence and Congo red staining.[11]
Congo red.

Interface dermatitis with lichenoid inflammation, not otherwise specified, can be caused by lichen planus-like keratosis, lichenoid actinic keratosis, lichenoid lupus erythematosus, lichenoid GVHD (chronic GVHD), pigmented purpuric dermatosis, pityriasis rosea, and pityriasis lichenoides chronica.[1] Unusual conditions that can be associated with a lichenoid inflammatory cell infiltrate are HIV dermatitis, syphilis, mycosis fungoides, urticaria pigmentosa, and post-inflammatory hyperpigmentation.[1] In cases of post-inflammatory hyperpigmentation, it is important to exclude potentially harmful mimics such as a regressed melanocytic lesion or lichenoid pigmented actinic keratosis.[1]

Psoriaform dermatitis

Examining multiple deeper levels is recommended if initial cuts do not correlate well with the clinical history.[1]

Psoriaform dermatitis typically displays:[1]

  • Regular epidermal hyperplasia, elongation of the rete ridges, hyperkeratosis, and parakeratosis.
  • Usually:A superficial perivascular inflammatory infiltrate
  • Often: Thinning of epidermal cells overlying the tips of dermal papillae (suprapapillary plates), and dilated, tortuous blood vessels within these papillae

Further histopathologic diagnosis is performed by the following parameters:

Psoriasiform dermatitis[1]
Condition Hyperkeratosis Parakeratosis Acanthosis Suprapapillary plate Spinous cell layer changes Other distinctive feature Micrograph
Psoriasis Present Diffuse Regular Thin Increased mitoses; minimal spongiosis
Clubbed rete pegs[12] [13]
  • Microabscesses
  • Thin or absent granular cell layer
Micrograph of psoriasis vulgaris.jpg
Psoriasiform drug reaction Present Focal Regular and irregular Normal or thick Spongiosis; eosinophilic infiltrate Basal cell layer with inflammatory cells; Civatte bodies
Chronic allergic/contact and atopic dermatitis Present Focal; crust may be present Irregular Normal or thick Spongiosis; eosinophilic infiltrate
Fungal infection Compact Focal; crust may be present Irregular Normal or thick Occasional neutrophiles;
Lichen simplex chronicus Present Focal; thick crust Regular or irregular Thin or thick ±minimal inflammatory infiltrate Thickened granular cell layer
Scabies Present Focal or diffuse Irregular Normal or thick Inflammatory infiltrate; eosinophilic spongiosis
Seborrheic dermatitis and HIV dermatitis Present Focal Irregular Normal or thick Spongiosis; lymphocytic and neutrophilic infiltrate
Pityriasis rubra pilaris Compact Shoulder parakeratosis[note 4]; alternating orthokeratosis and parakeratosis Regular or irregular Normal or thick Spongiosis; lymphocytic infiltrate; rare acantholysis
Pityriasis rosea Present Focal Irregular Normal or thick Small foci of spongiosis; lymphocytic infiltrate Occasional necrotic keratinocytes of basal layer
Syphilis Present Focal Regular or irregular Normal or thick Lymphocytes and neutrophils Basal layer interface change
Pityriasis lichenoides chronica Present Caps of parakeratosis Irregular Normal Mild spongiosis, lymphocytic infiltrate; necrotic keratinocytes Necrotic keratinocytes of basal layer
Mycosis fungoides Present Focal Regular or irregular Normal Minimal or no spongiosis; ±Pautrier microabscess Atypical lymphoid cells lining the dermo–epidermal junction
Pautrier microabscesses

Non vesicullobullous, non-pustular lesions without epidermal changes

Lymphocytic infiltrate

Main conditions[1] Characteristics Micrograph Photograph
Urticaria, lymphocyte predominant Perivascular location. Mast cells are relatively sparse, potentially demonstrated with special stains, preferably tryptase stain. Extravasated erythrocytes are present in about 50% of the cases. No vasculitis.[14] Micrograph of urticaria.jpg Dermal edema [solid arrows in (A,B)] and a sparse superficial predominantly perivascular and interstitial infiltrate of lymphocytes and eosinophils without signs of vasculitis (dashed arrow).[15] Urticaria near navel.jpg
Fungal skin infection Often visible fungus. Other signs depend on fungus species.[16]
Pigmented purpuric dermatosis
  • Perivascular infiltrate, but may involve the dermis, further away from blood vessels.[17]
  • Sometimes tendency for lichenoid infiltrate[note 5][17]
  • Mild vascular damage, mainly endothelial swelling and focal karyorrhectic debris.[17]
  • Red blood cell extravasation.[17]
  • The epidermis may be normal or may exhibit spongiosis, focal parakeratosis, exocytosis and/or vacuolar change.[17]
Histopathology of Schamberg disease.jpg Schambergdisease-26male.png
Erythema annulare centrifugum
  • Superficial types:[18]
  • Mild spongiosis, parakeratosis and microvesiculation.
  • "Coat-sleeve anomaly": tight lymphohistiocytic infiltrate surrounding superficial vessels

Deep lesions: Sharply demarcated perivascular mononuclear cell infiltrate in middle to deep dermis[18]

Micrograph of erythema annulare centrifugum.jpg Erythema annulare centrifugum on arms and legs.jpg
Not otherwise specified[note 3] A lesion with superficial lymphocytic infiltrate without additional histopathologic characteristics can be due to for example drug reactions and insect bites.[1][note 3]

Lymphoeosinophilic infiltrate

Main conditions[1] Characteristics Micrograph Photograph
Urticaria, lymphocyte predominant Perivascular location. Mast cells are relatively sparse, potentially demonstrated with special stains, preferably tryptase stain. Extravasated erythrocytes are present in about 50% of the cases. No vasculitis.[14] Micrograph of urticaria.jpg Dermal edema (solid arrows) and a sparse superficial predominantly perivascular and interstitial infiltrate of lymphocytes and eosinophils (dashed arrow) Urticaria near navel.jpg
Prevesicular stage of bullous pemphigoid Image at right shows influx of inflammatory cells including eosinophils and neutrophils in the dermis (solid arrow) and blister cavity (dashed arrows), and deposition of fibrin (asterisks).[19] However, the diagnosis of bullous pemphigoid consist of at least 2 positive results out of 3 criteria:[20]
  • Pruritus and/or predominant cutaneous blisters
  • Linear IgG and/or C3c deposits (in an n- serrated pattern) by direct immunofluorescence microscopy (DIF)
  • Positive epidermal side staining by indirect immunofluorescence microscopy on human salt-split skin (IIF SSS) on a serum sample.
Micrograph of infiltrate in bullous pemphigoid.jpg
Not otherwise specified[note 3] A lesion with superficial lymphoeosinophilic infiltrate without additional histopathologic characteristics can be due to for example drug reactions and insect bites.[1][note 3]

Lymphoplasmacytic infiltrate

Main conditions[1] Characteristics Micrograph Photograph
Rosacea Typically enlarged, dilated capillaries and venules located in the upper dermis, angulated telangiectasias, perivascular and perifollicular lymphocytic infiltration, and superficial dermal edema.[21] Micrograph of rosacea.jpg Rosacea.jpg
Secondary syphilis Various, but often one or a combination of:[22]
  • Psoriasiform hyperplasia with superficial neutrophils
  • Lichenoid tissue reaction, epidermal apoptosis and exocytosis of neutrophils
  • Superficial and deep chronic infiltrate in the dermis
  • Often numerous plasma cells in about 1/3 of cases
  • Often endothelial swelling.
Micrograph of secondary syphilis, HE.jpg Secondary stage syphilis sores (lesions) on the soles of the feet. Plantar lesions-CDC.jpg
Erythema migrans Typically a superficial and deep perivascular lymphocytic infiltrate.[23] Plasma cells are typically located at the periphery of the lesion, whereas eosinophils are in the center.[23] Erythema migrans - erythematous rash in Lyme disease - PHIL 9875.jpg
Kaposi’s sarcoma in patch stage The patch stage typically shows irregular proliferation of jagged vascular channels in the dermis below an integral epidermis. The so-called promontory sign is sometimes found in patch stage lesions and denotes vascular spaces surrounding pre-existing blood (see image).[24]

vessels

Micrograph of promontory sign of kaposi's sarcoma.jpg Patch stage Kaposi's sarcoma.jpg
Not otherwise specified[note 3] A lesion with superficial lymphoplasmacytic infiltrate without additional histopathologic characteristics can be due to for example trauma, ulceration, scar and early cutaneous connective tissue diseases.[1][note 3]

Mastocytosis

Main conditions[1] Characteristics Micrograph Photograph
Urticaria pigmentosa Mastocytosis with a clinical picture of darkish spots. Histopathology of urticaria pigmentosa.jpg Urticaria pigmentosa lesions on a child.jpg
Not otherwise specified[note 3] Includes the rare disease of primary mastocytosis.[1][note 3]

Lymphohistiocytic infiltrate

Leprosy

These include bacterial infections including leprosy, and the sample should therefore be stained with Ziel-Neelsen, acid fast stains, Gomori methenamine silver, PAS, and Fite stains.[1] If negative, an unspecific lymphohistocytic dermatosis may be caused by drug reactions and viral infections.[1][note 3]

Granulomatous inflammation

Further information: Granulomatous skin inflammation Granulomatous inflammation is defined by the presence of mononuclear leukocytes, specifically histiocytes, appearing as epithelioid cells with round to oval nuclei, often with irregular contours and abundant granular eosinophilic cytoplasm with indistinct cell borders. They may also coalesce to form multinucleated giant cells.[25]

Neutrophilic infiltrate

Main conditions[1] Characteristics Micrograph Photograph
Urticaria, neutrophil predominant
  • Interstitial location[14]
  • Relatively dense infiltrate[14]
  • Mast cells are relatively sparse, potentially demonstrated with special stains, preferably tryptase stain.[14]
  • Extravasated erythrocytes are present in about 50% of the cases [14]
  • No vasculitis.[14]
Micrograph of neutrophilic urticarial dermatosis.jpg Neutrophilic urticarial dermatosis.jpg
Dermatitis herpetiformis
  • Subepidermal vesicles and blisters associated with accumulation of neutrophils at the papillary tips.[26]
  • Sometimes presence of eosinophils, giving an appearance similar to bullous pemphigoid.[26]
  • The histopathology is unspecific in approximately 35%–40% of the cases,[26] and direct immunofluorescence is needed, showing deposition of IgA in the papillary dermis in a granular or fibrillar pattern.[27]
Micrograph of dermatitis herpetiformis.jpg Dermatitis herpetiformis.jpg
Early linear IgA bullous dermatosis Subepidermal blister formation.[28] Micrograph of linear IgA bullous dermatosis.jpg Linear IgA bullous dermatosis.jpg
Early febrile neutrophilic dermatosis (Sweet's syndrome) Neutrophilic and lymphohistiocytic infiltrate and edema.[29] Sweet's syndrome pathology.jpg Sweet's syndrome Crohn's disease.gif
Connective tissue disorders
  • Usually associated with epidermal changes.[1] (Systemic lupus erythematosis pictured)
File:Histopathology of systemic lupus erythematosus.jpg Butterfly rash of lupus erythematosus.jpg
Cutaneous small-vessel vasculitis
  • Neutrophils with nuclear dust (dashed arrows in image), with high affinity for postcapillary venules.[30]
  • Features of vascular injury: fibrinoid necrosis (asterisks) and erytrocyt extravasation (solid arrows)
Micrograph of cutaneous small-vessel vasculitis.jpg Cutaneous small-vessel vasculitis.jpg
Acute inflammation (not otherwise specified)
  • Neutrophilic infiltrate not conforming to any of the above mentioned conditions.
Dermal edema in a case of cellulitis.

No visible pathology

In a referral with a rash or other suspicion of dermatitis, but no visible pathology is seen, generally do a fungal stain, as fungal infections may have no visible pathology on H&E stain.

Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
  2. PAS is for evaluation of the epidermal basement membrane, blood vessels, and the presence of fungal organisms
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 In "not otherwise specified" cases, a description of the findings attained so far is generally enough as a diagnosis, but may mention when it can be consistent with a diagnosis that is clinically suspected according to the referral. A more comprehensive approach is to include a comment such as the following:
    "Differential diagnosis for this condition include: ____, ____ and ____. Clinical correlation is recommended.
  4. Parakeratotic mounds at the edge of follicular ostia.
  5. Pigmented purpuric dermatitis of Gougerot and Blum particularly have a tendency for lichenoid infiltrate.

Main page

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 1.29 1.30 1.31 1.32 1.33 1.34 1.35 Alsaad, K O (2005). "My approach to superficial inflammatory dermatoses ". Journal of Clinical Pathology 58 (12): 1233–1241. doi:10.1136/jcp.2005.027151. ISSN 0021-9746. 
  2. Page 678 in: Chhabra, Seema; Minz, RanjanaWalker; Saikia, Biman (2012). "Immunofluorescence in dermatology ". Indian Journal of Dermatology, Venereology, and Leprology 78 (6): 677. doi:10.4103/0378-6323.102355. ISSN 0378-6323. Archived from the original. . 
  3. Katarzyna Lundmark, Krynitz, Ismini Vassilaki, Lena Mölne, Annika Ternesten Bratel. Handläggning av hudprover – provtagningsanvisningar, utskärningsprinciper och snittning (Handling of skin samples - Instructions for sampling, cutting and incision. KVAST (Swedish Society of Pathology). Retrieved on 2019-09-09.
  4. ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  5. 5.0 5.1 5.2 Mowafak Hamodat. Skin inflammatory (nontumor) > Spongiotic, psoriasiform and pustular reaction patterns > Seborrheic dermatitis. PathologyOutlines.com. Topic Completed: 1 August 2011. Revised: 26 March 2019
  6. 6.0 6.1 6.2 6.3 6.4 6.5 Unless else specified in boxes, reference is: Alsaad, K O (2005). "My approach to superficial inflammatory dermatoses ". Journal of Clinical Pathology 58 (12): 1233–1241. doi:10.1136/jcp.2005.027151. ISSN 0021-9746. 
  7. Lisa K Pappas-Taffer. Lichen Sclerosus. Medscape. Updated: May 17, 2018
  8. Mowafak Hamodat. Skin inflammatory (nontumor) > Lichenoid and interface reaction patterns > Lupus: systemic lupus erythematosus (SLE). PathologyOutlines. Topic Completed: 1 August 2011. Revised: 26 March 2019
  9. 9.0 9.1 9.2 Gorouhi, Farzam; Davari, Parastoo; Fazel, Nasim (2014). "Cutaneous and Mucosal Lichen Planus: A Comprehensive Review of Clinical Subtypes, Risk Factors, Diagnosis, and Prognosis ". The Scientific World Journal 2014: 1–22. doi:10.1155/2014/742826. ISSN 2356-6140. 
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  10. "Generalized lichen nitidus ". Pediatr Dermatol 22 (2): 158–60. 2005. doi:10.1111/j.1525-1470.2005.22215.x. PMID 15804308. 
  11. Shenoi, SD; Balachandran, C; Mehta, VandanaRai; Salim, T (2005). "Lichen amyloidosus: A study of clinical, histopathologic and immunofluorescence findings in 30 cases ". Indian Journal of Dermatology, Venereology and Leprology 71 (3): 166. doi:10.4103/0378-6323.16230. ISSN 0378-6323. 
  12. "Cytokines and cytokine profiles in human autoimmune diseases and animal models of autoimmunity ". Mediators of Inflammation 2009: 1–20. 2009. doi:10.1155/2009/979258. PMID 19884985. 
  13. "Diagnosis and classification of psoriasis ". Autoimmunity Reviews 13 (4–5): 490–5. January 2014. doi:10.1016/j.autrev.2014.01.008. PMID 24434359. 
  14. 14.0 14.1 14.2 14.3 14.4 14.5 14.6 Barzilai, Aviv; Sagi, Lior; Baum, Sharon; Trau, Henri; Schvimer, Michael; Barshack, Iris; Solomon, Michal (2017). "The Histopathology of Urticaria Revisited—Clinical Pathological Study ". The American Journal of Dermatopathology 39 (10): 753–759. doi:10.1097/DAD.0000000000000786. ISSN 0193-1091. 
  15. Giang, Jenny; Seelen, Marc A. J.; van Doorn, Martijn B. A.; Rissmann, Robert; Prens, Errol P.; Damman, Jeffrey (2018). "Complement Activation in Inflammatory Skin Diseases ". Frontiers in Immunology 9. doi:10.3389/fimmu.2018.00639. ISSN 1664-3224. 
  16. Guarner, J.; Brandt, M. E. (2011). "Histopathologic Diagnosis of Fungal Infections in the 21st Century ". Clinical Microbiology Reviews 24 (2): 247–280. doi:10.1128/CMR.00053-10. ISSN 0893-8512. 
  17. 17.0 17.1 17.2 17.3 17.4 Stephen Lyle. Pigmented purpuric dermatoses. Dermpedia.org. Retrieved on 2019-11-05.
  18. 18.0 18.1 . Histology of erythema annulare centrifugum. DermNet NZ. Retrieved on 2019-11-05.
  19. Giang, Jenny; Seelen, Marc A. J.; van Doorn, Martijn B. A.; Rissmann, Robert; Prens, Errol P.; Damman, Jeffrey (2018). "Complement Activation in Inflammatory Skin Diseases ". Frontiers in Immunology 9. doi:10.3389/fimmu.2018.00639. ISSN 1664-3224. 
  20. "Assessment of diagnostic strategy for early recognition of bullous and nonbullous variants of pemphigoid. ". JAMA Dermatol 155 (2): 158–165. December 2018. doi:10.1001/jamadermatol.2018.4390. PMID 30624575. 
  21. Celiker, Hande; Toker, Ebru; Ergun, Tulin; Cinel, Leyla (2017). "An unusual presentation of ocular rosacea ". Arquivos Brasileiros de Oftalmologia 80 (6). doi:10.5935/0004-2749.20170097. ISSN 0004-2749. 
  22. Assoc Prof Patrick Emanuel (2013). Syphilis pathology. Dermnet NZ.
  23. 23.0 23.1 Wilson, Thomas C.; Legler, Allison; Madison, Kathi C.; Fairley, Janet A.; Swick, Brian L. (2012). "Erythema Migrans ". The American Journal of Dermatopathology 34 (8): 834–837. doi:10.1097/DAD.0b013e31825879be. ISSN 0193-1091. 
  24. Soyer, H. Peter; Jakob, Lena; Metzler, Gisela; Chen, Ko-Ming; Garbe, Claus (2011). "Non-AIDS Associated Kaposi's Sarcoma: Clinical Features and Treatment Outcome ". PLoS ONE 6 (4): e18397. doi:10.1371/journal.pone.0018397. ISSN 1932-6203. 
  25. Shah, Kabeer K.; Pritt, Bobbi S.; Alexander, Mariam P. (2017). "Histopathologic review of granulomatous inflammation ". Journal of Clinical Tuberculosis and Other Mycobacterial Diseases 7: 1–12. doi:10.1016/j.jctube.2017.02.001. ISSN 24055794. 
  26. 26.0 26.1 26.2 Antiga, Emiliano; Caproni, Marzia (2015). "The diagnosis and treatment of dermatitis herpetiformis ". Clinical, Cosmetic and Investigational Dermatology: 257. doi:10.2147/CCID.S69127. ISSN 1178-7015. 
  27. Huma A. Mirza; Amani Gharbi; William Gossman.. Dermatitis Herpetiformis. StatPearls at National Center for Biotechnology Information. Last Update: July 11, 2019.
  28. Saleem, Maryam; Iftikhar, Hassaan (2019). "Linear IgA Disease: A Rare Complication of Vancomycin ". Cureus. doi:10.7759/cureus.4848. ISSN 2168-8184. 
  29. Casarin Costa, Jose Ricardo; Virgens, Anangelica Rodrigues; de Oliveira Mestre, Luisa; Dias, Natasha Favoretto; Samorano, Luciana Paula; Valente, Neusa Yuriko Sakai; Festa Neto, Cyro (2017). "Sweet Syndrome: Clinical Features, Histopathology, and Associations of 83 Cases ". Journal of Cutaneous Medicine and Surgery 21 (3): 211–216. doi:10.1177/1203475417690719. ISSN 1203-4754. 
  30. Giang, Jenny; Seelen, Marc A. J.; van Doorn, Martijn B. A.; Rissmann, Robert; Prens, Errol P.; Damman, Jeffrey (2018). "Complement Activation in Inflammatory Skin Diseases ". Frontiers in Immunology 9. doi:10.3389/fimmu.2018.00639. ISSN 1664-3224. 
    • "Figures - available via license: CC BY 4.0"

Image sources


Benign non-inflammatory skin conditions

Author: Mikael Häggström [note 1]
These are aberrations that do not display signs of suspected malignant excisions or dermatitis. These may present as skin cysts.

Fixation

Generally 10% neutral buffered formalin.

  See also: General notes on fixation


Gross processing

Gross pathology processing of skin lesions with benign appearance, by lesion size:[1]
<4 mm 4 - 8 mm 9 - 15 mm

Tissue selection from skin excision with lesion less than 4 mm with benign appearance.png

Tissue selection from skin excision with lesion 4-8 mm with benign appearance.png

Tissue selection from skin excision with lesion 9-15 mm with benign appearance.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

The primary objective is to determine the location, and then the most likely cell type of the aberration:

Epidermis

Dermis

Fatty tissue

Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.

Main page

References

  1. ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  2. Sato, Toshitsugu; Tanaka, Masaru (2014). "Linear sebaceous hyperplasia on the chest ". Dermatology Practical & Conceptual. doi:10.5826/dpc.0401a16. ISSN 21609381. 
  3. Rabello, FB; Souza, CD; Farina Jr, JA (2014). "Update on hypertrophic scar treatment ". Clinics 69 (8): 565–573. doi:10.6061/clinics/2014(08)11. ISSN 18075932. 

Image sources


Keloid

Author: Mikael Häggström [note 1]

Gross processing

Gross pathology processing of skin lesions with benign appearance, by lesion size:[1]
<4 mm 4 - 8 mm 9 - 15 mm

Tissue selection from skin excision with lesion less than 4 mm with benign appearance.png

Tissue selection from skin excision with lesion 4-8 mm with benign appearance.png

Tissue selection from skin excision with lesion 9-15 mm with benign appearance.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

A keloid is characterized by wide bands of collagen with large, brightly eosinophilic, glassy fibers, parallel to fibroblasts and myofibroblasts.
Keloid versus hypertrophic scar - Typical findings
Keloid Hypertrophic scar
Histopathology of a keloid.jpg Histopathology of a hypertrophic scar, medium magnification.jpg
Flattening of the overlying epidermis No Yes
Scarring of the papillary dermis No Yes
Collagen Thick hyalinized bundles Whorl-like or nodular arrangements
Vertically oriented blood vessels Yes No
Prominent disarray of fibrous fascicles/nodules Yes No
Tongue-like advancing edge underneath normal-appearing epidermis and papillary dermis Yes No
Horizontal cellular fibrous band in the upper reticular dermis Yes No
Prominent fascia-like fibrous band Yes No

Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.

Main page

References

  1. ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.

Image sources


Hypertrophic scar

Author: Mikael Häggström [note 1]

Gross processing

Gross pathology processing of skin lesions with benign appearance, by lesion size:[1]
<4 mm 4 - 8 mm 9 - 15 mm

Tissue selection from skin excision with lesion less than 4 mm with benign appearance.png

Tissue selection from skin excision with lesion 4-8 mm with benign appearance.png

Tissue selection from skin excision with lesion 9-15 mm with benign appearance.png

In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions

Microscopic evaluation

A hypertrophic scar is characterized by replacement of the papillary and reticular dermis by scar tissue with prominent vertically oriented blood vessels.[2]
Keloid versus hypertrophic scar - Typical findings
Keloid Hypertrophic scar
Histopathology of a keloid.jpg Histopathology of a hypertrophic scar, medium magnification.jpg
Flattening of the overlying epidermis No Yes
Scarring of the papillary dermis No Yes
Collagen Thick hyalinized bundles Whorl-like or nodular arrangements
Vertically oriented blood vessels Yes No
Prominent disarray of fibrous fascicles/nodules Yes No
Tongue-like advancing edge underneath normal-appearing epidermis and papillary dermis Yes No
Horizontal cellular fibrous band in the upper reticular dermis Yes No
Prominent fascia-like fibrous band Yes No

Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.

Main page

References

  1. ". Ochsner J 5 (2): 22–33. 2003. PMID 22826680. PMC: 3399331. Archived from the original. . 
    - With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
    - It also shows an example of circular coverage, with equal coverage distance in all four directions.
    - The entire specimen may be submitted if the risk of malignancy is high.
  2. Rabello, FB; Souza, CD; Farina Jr, JA (2014). "Update on hypertrophic scar treatment ". Clinics 69 (8): 565–573. doi:10.6061/clinics/2014(08)11. ISSN 18075932. 

Image sources


Notes


Main page

References


Image sources