Junctional nevus: Difference between revisions

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Suspected dysplastic nevus (also called dysplastic melanocytic nevus).
[[File:Histopathology of melanocytic nevus 2.jpg|thumb|350px|'''Junctional nevus''' (here seen in H&E stain and Melan A stain), where all nests are continuous with the epidermis.]]
{{Comprehensiveness}}
A suspected dysplastic nevus (also called dysplastic melanocytic nevus) generally presents as a [[Dark skin focalities|dark skin focality]].
{{Fixation - standard}}
{{Gross processing of skin excisions}}
==Microscopic evaluation==
A junctional nevus is characterized by:<ref>{{cite web|url=https://www.pathologyoutlines.com/topic/skintumormelanocyticJunctnevus.html|title=Skin melanocytic tumor - Nevi - Junctional nevus|author=Christopher S. Hale, M.D.|website=Pathology Outlines}} Topic Completed: 1 February 2017. Revised: 4 April 2019</ref>
*Rounded melanocyte nests on the epidermal side of dermoepidermal junction
*Variable lentiginous melanocytic hyperplasia


==Evaluation==
===Differential diagnosis===
<gallery mode=packed heights=200>
File:Histopathology of lentigo maligna.jpg|'''[[Melanoma in situ]]''', by higher atypia and dysplasia (see table in [[#Grading|the grading section]]).
File:Histopathology of dermal nevus, high magnification.jpg|'''[[Dermal nevus]]''', with nevus cells enclosed within the dermis.
File:Histopathology of compound nevus.jpg|thumb|'''Compound nevus''', with nevus cells in both dermis and epidermis.
</gallery>
*'''[[Epidermal nevus]]''', nests of nevus cells enclosed within the epidermis.


===Swedish approach===
===Grading===
Review of '''clinical information''', mainly:<ref name=KVAST>{{cite web|author=Katarzyna Lundmark, Britta Krynitz, Ismini Vassilaki, Lena Mölne, Annika Ternesten Bratel|title=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)|url=https://medlem.foreningssupport.se/foreningar/uploads/L15178/kvast/hud/Histopatologisk%20bedomning%20och%20gradering%20av%20dysplastiskt%20nevus%20samt%20gransdragning%20mot%20melanom%20in%20situ-melanom%2020150330.pdf|website=KVAST (Swedish Society of Pathology)|accessdate=2019-09-18}}</ref>
{{Epidermal and junctional nevus grading}}
*Growth
[[File:SOX10 immunohistochemistry of normal skin (edited).jpg|thumb|center|300px|In contrast, normal skin (pictured) has a melanocyte about every 4 cells along the basement membrane.]]
*Abnormal visual appearance
*Size >10mm


'''Microscopy'''<br>Classify into either of the following:
===Report===
 
*Presence or absence of atypia.
{|class="wikitable"
:{{Moderate-begin}}If atypical, low-or high grade, or degree of atypia.{{Moderate-end}}
!rowspan=2| Parameter !!colspan=2| Low-grade dysplasia !! High-grade dysplasia !!rowspan=2| Suspected melanoma in situ
*{{Comprehensive-begin}}Size
|-
*Findings included in table above if applicable.
| Mild || Moderate || Severe
*Most likely grade if possible.{{Comprehensive-end}}
|-
{|class=wikitable
| Delimitation || Rarely diffuse || Sometimes diffuse || Often diffuse || Often diffuse
| Skin, upper back, excision:<br>- Junctional {{Moderate-begin}}melanocytic{{Moderate-end}} nevus with {{Moderate-begin}}moderate{{Moderate-end}} atypia.
|-
| Lentiginous proliferation || 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 [[File:Histopathology of lentigo maligna.jpg|center|140px]]
|-
|
<!--Irregular
second distribution *
Yes
Yes
Yes
Yes
Brewing Rarely Often Often Often Often
Confluence of Almost Rarely Sometimes Often Often Widespread
Pigment Distribution Regular Irregular Irregular Irregular Irregular
Suprabasal growing up No Yes Yes Yes, multifocal
structural
abnormalities
Pagetoid migration No No Yes, for a maximum of 2
HPF centrally,
but not peripherally
Yes, multifocal
and / or i
periphery
Dominant
atypigrad
Easy
Easy-moderate
Moderate-severe
Moderate-severe
cellular
atypia *
Percentage of atypical
melanocytes
<10%
about 10 - 50%
about 50-90%
Usually> 90%
Extended retelists
Yes,
regular
Yes, varying
Yes, often
irregular
Varying,
planarized
Concentric fibrosis Yes Yes Yes Varies
Lamellar fibrosis Rarely Often Often Pronounced Varying
lymphocytic *
Sparingly,
perivascular
Easy-moderate
perivascular
Varying
Varying
reactive
changes
regressive
changes
No
No
Rarely
Varying
Melanocytic atypia
No
Rarely, in superficial
part
Can be detected in
superficial part
Can be detected in
superficial part.
intradermal
component
maturation
Yes
Yes, can be
partial
Yes, can be
partial
Yes, can be
partial; if
No
ripening
recital
invasive
melanoma!
! Further workup !!  !!  !!  Immunohistochemistry
|}
 
 
 
 
Microscopy at low magnification (x4):
*Intraepidermal or composite lesion?
*Structural abnormalities in the intraepidermal component?
• Asymmetry?
• Boundary: well-defined / diffusely bounded?
• Shoulder phenomenon?
• Lentiginous and / or second form?
• Regular / irregular distribution of the nest?
• Bridge formation between the nest?
• Confluence of the neighbor?
• Pigment distribution in the lesion: regular / irregular?
• Suprabasal growth (in the basal 2/3 parts of the epidermis)?
• Pagetoid migration (in the upper 1/3 part of the epidermis)?
Are there reactive changes?
• Irregular and / or extended retelists?
• Fibros around retails? Concentric and / or lamellar? Ärrliknande? A sign of
past trauma or surgery?
• Lymphocyte infiltrate? Perivascular or diffuse / ligamentous? Thrifty or
pronounced?
• Regressive changes?
Enlarge (x 10-20)
Are there cellular abnormalities in the intraepidermal component?
• Melanocytic atypia?
• Which atypical degree dominates? Easy? Moderate? Grave?
• What proportion of melanocytes are atypical?
• Suprabasal growth (in the basal 2/3 parts of the epidermis) of atypical melanocytes?
• Pagetoid migration (in the upper 1/3 part of the epidermis) of atypical melanocytes?
Is there melanocytic atypia in the intradermal component?
• Only in the superficial part?
• “Matured”?
• Mitoses?
Assess radicalism
When does the change in preparation edge / resection edge?
-->
|}
|}
{{Reporting}}
{{Bottom}}
{{Bottom}}