Difference between revisions of "Tubular and ⁄or villous adenoma"
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==Microscopic evaluation== | ==Microscopic evaluation== | ||
| − | {{ | + | ===Criteria=== |
| − | === | + | [[File:Tubular adenoma with low-grade dysplasia.jpg|thumb|Tubular adenoma with low-grade dysplasia.]] |
| − | {|class="wikitable | + | Dysplastic changes should involve at least the upper half of the crypts and the luminal surface.<ref name=stanford-criteria>{{cite web|url=http://surgpathcriteria.stanford.edu/gitumors/colorectal-adenoma/|title=Adenoma of the Colon and Rectum|author=Robert V Rouse|website=Stanford University School of Medicine}} Original posting/last update : 1/31/10, 1/19/14</ref> |
| − | |+ | + | *'''Nuclear dysplasia''' is mandatory to diagnose adenoma. It involves enlarged hyperchromatic nuclei that are oval or frequently elongated, and with high nucleus to cytoplasm ratio.<ref name=stanford-criteria/> |
| − | ! | + | *Often '''nuclear stratification''' and '''loss of polarity'''<ref name=stanford-criteria/> |
| + | *Always changes in gland architecture, such as:<ref name=stanford-criteria/> | ||
| + | :*'''Enlarged crypts''' | ||
| + | :*Gland '''budding''', or otherwise irregular glands<ref name=stanford-criteria/> | ||
| + | *'''Mucin depletion''' is often seen, but is not required<ref name=stanford-criteria/> | ||
| + | |||
| + | ===Low or high grade=== | ||
| + | In '''low-grade''' lesions, the crypts should maintain a resemblance to normal colon.<ref name=Myers2019/> | ||
| + | |||
| + | '''High grade''' lesions typically have: | ||
| + | *'''Cribriform architecture''', consisting of juxtaposed gland lumens without stroma in between, with loss of cell polarity. Rarely, they have foci of squamous differentiation (morules). This should be distinguished from cases where piles of well-differentiated mucin-producing cells appear cribriform. In such piles, nuclei show regular polarity with apical mucin, and their nuclei are not markedly enlarged. | ||
| + | *Increased '''nucleus to cytoplasm ratio'''.<ref name=Myers2019/> | ||
| + | *More "open" appearing '''nuclei''' with increasingly prominent nucleoli<ref name=Myers2019/> | ||
| + | *Back-to-back glands<ref name=Myers2019/> | ||
| + | |||
| + | <gallery heights=220 mode=packed> | ||
| + | File:Tubular adenoma with high grade dysplasia.jpg|Tubular adenoma with high-grade dysplasia. | ||
| + | </gallery> | ||
| + | |||
| + | {|class="wikitable" | ||
| + | |+Typical findings in low-grade versus high-grade tubular and ⁄or villous adenoma | ||
| + | ! !! Low-grade<ref name=Myers2019>{{cite web|url=https://www.ncbi.nlm.nih.gov/books/NBK470272/|title=Villous Adenoma|author=David J. Myers; Komal Arora|website=StatPearls, National Center for Biotechnology Information}} Last Update: June 18, 2019.<br>-"This book is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/)"</ref> !! High grade<ref name=Myers2019/> | ||
| + | |- | ||
| + | !Crowding | ||
| + | | Pseudo-stratification to early stratification || More substantial stratification | ||
|- | |- | ||
| − | ! | + | ! Pleomorphism and atypical mitoses |
| − | | | + | | Absent or minimally present || Present |
| − | | | ||
|- | |- | ||
| − | ! | + | ! Loss of cell polarity |
| − | | | + | | Minimal || More significant |
| − | |||
| − | |||
|- | |- | ||
| − | ! | + | ! Crowding, cribriform, or complex forms |
| − | + | | No significant || Present | |
| − | | | ||
| − | | | ||
|} | |} | ||
| − | |||
===Differential diagnoses=== | ===Differential diagnoses=== | ||
| Line 50: | Line 68: | ||
:*Frequenty '''desmoplasia''' | :*Frequenty '''desmoplasia''' | ||
:*'''Dirty necrosis''', consisting of extensive central necrosis with granular eosinophilic karyorrhectic debris. Garland of cribriform glands are frequently found in their vicinity. | :*'''Dirty necrosis''', consisting of extensive central necrosis with granular eosinophilic karyorrhectic debris. Garland of cribriform glands are frequently found in their vicinity. | ||
| + | |||
| + | ===Tubular or villous=== | ||
| + | {|class="wikitable" align="center" | ||
| + | |+ Colorectal adenoma | ||
| + | ! Type !! Risk of containing malignant cells !! Histopathology !! Image | ||
| + | |- | ||
| + | ! Tubular adenoma | ||
| + | | '''2%''' at 1.5cm<ref>{{cite web|url=https://www.msdmanuals.com/professional/gastrointestinal-disorders/tumors-of-the-gastrointestinal-tract/polyps-of-the-colon-and-rectum|title=Polyps of the Colon and Rectum|author=Minhhuyen Nguyen|website=MSD Manual}} Last full review/revision June 2019</ref> || Over 75% of volume has tubular appearance.<ref name=WHO>{{cite book | last=Bosman | first=F. T. | title=WHO classification of tumours of the digestive system | publisher=International Agency for Research on Cancer | publication-place=Lyon | year=2010 | isbn=92-832-2432-9 | oclc=688585784 | ref=harv}}</ref> | ||
| + | | [[File:Tubular adenoma of the colon.jpg|180px]] | ||
| + | |- | ||
| + | ! Tubulovillous adenoma | ||
| + | | '''20%''' to '''25%'''<ref name="AmersiAgustin2005">{{cite journal|last1=Amersi|first1=Farin|last2=Agustin|first2=Michelle|last3=Ko|first3=Clifford Y|title=Colorectal Cancer: Epidemiology, Risk Factors, and Health Services|journal=Clinics in Colon and Rectal Surgery|volume=18|issue=03|year=2005|pages=133–140|issn=1531-0043|doi=10.1055/s-2005-916274}}</ref> | ||
| + | | 25%-75% villous<ref name=WHO/> | ||
| + | | [[File:Micrograph of tubulovillous adenoma.jpg|180px]] | ||
| + | |- | ||
| + | ! Villous adenoma | ||
| + | | '''15%'''<ref name=Ramji2016>{{cite web|url=https://emedicine.medscape.com/article/170283-followup#e3|title=Villous Adenoma Follow-up|website=Medscape|author=Alnoor Ramji}} Updated: Oct 24, 2016</ref> to '''40%'''<ref name="AmersiAgustin2005"/> | ||
| + | | Over 75% villous<ref name=WHO/> | ||
| + | | [[File:Villous adenoma of the colorectum (high power view).jpg|180px]] | ||
| + | |} | ||
| + | Length of villi must be at least twice the depth of the normal mucosal thickness.<ref name=stanford-criteria/> | ||
{{Evaluation of tumors}} | {{Evaluation of tumors}} | ||
| + | |||
===Further workup=== | ===Further workup=== | ||
Dissecting pools of mucin at the base of any adenoma should be evaluated for the possibility of mucinous carcinoma.<ref name=stanford-criteria/> | Dissecting pools of mucin at the base of any adenoma should be evaluated for the possibility of mucinous carcinoma.<ref name=stanford-criteria/> | ||
{{Bottom}} | {{Bottom}} | ||
Revision as of 11:08, 31 October 2019
Author:
Mikael Häggström [note 1]
Contents
Gross evaluation
Further information: Colon
Tissue selection and trimming
There is a separate article for the Grossing of minimally invasive colorectal surgery.
Depending on sample format:[1]
- Biopsies and polyps of <4 mm are embedded in their entirety. Samples less than 0.3 mm should be stained with eosin to avoid getting lost processing.
- Polyps 4-8 mm with short stem or without stem: Identify the excision surface and divide the polyp longitudinally through the excision surface.
- Polyps > 8 mm with a stem long enough to make it possible to take a transverse, whole slice from the stem closest to the excision surface: First, take a transverse slice through the peripheral portion of the stem, encompassing the entire circumference. Then take a 3-4 mm thick slice longitudinally through the polyp and the middle of the stem, after which the two remaining parts on either side are cut into equally thick slices, parallel to the previous slice.
- Polyps >8 mm with short stem or without stem: Identify the excision surface and cut out a 3-4 mm thick disk that extends longitudinally through the center of the excision surface. Then divide the two remaining portions into equally thick slices, parallel to the previous slice.
- Polyps that come in parts: Pick out the largest pieces, which are cut as similar as possible to above. Small fragments are sieved and embedded in a separate box.
Gross reporting
- Polyp and/or fragment sizes
- Presence or absence of stem of polyps
Example, for a gastrointestinal biopsy:
| Labeled: "Sigmoid colon biopsy". The specimen is received in formalin and consists of 4 fragments of pink-tan tissue with a vaguely recognizable mucosal surface, mixed with food-like material. The fragments measure 0.2-0.3 cm in greatest dimension. The entire specimen is submitted for microscopic examination in one cassette. |
Microscopic evaluation
Criteria
Dysplastic changes should involve at least the upper half of the crypts and the luminal surface.[2]
- Nuclear dysplasia is mandatory to diagnose adenoma. It involves enlarged hyperchromatic nuclei that are oval or frequently elongated, and with high nucleus to cytoplasm ratio.[2]
- Often nuclear stratification and loss of polarity[2]
- Always changes in gland architecture, such as:[2]
- Enlarged crypts
- Gland budding, or otherwise irregular glands[2]
- Mucin depletion is often seen, but is not required[2]
Low or high grade
In low-grade lesions, the crypts should maintain a resemblance to normal colon.[3]
High grade lesions typically have:
- Cribriform architecture, consisting of juxtaposed gland lumens without stroma in between, with loss of cell polarity. Rarely, they have foci of squamous differentiation (morules). This should be distinguished from cases where piles of well-differentiated mucin-producing cells appear cribriform. In such piles, nuclei show regular polarity with apical mucin, and their nuclei are not markedly enlarged.
- Increased nucleus to cytoplasm ratio.[3]
- More "open" appearing nuclei with increasingly prominent nucleoli[3]
- Back-to-back glands[3]
Tubular adenoma with high-grade dysplasia.
| Low-grade[3] | High grade[3] | |
|---|---|---|
| Crowding | Pseudo-stratification to early stratification | More substantial stratification |
| Pleomorphism and atypical mitoses | Absent or minimally present | Present |
| Loss of cell polarity | Minimal | More significant |
| Crowding, cribriform, or complex forms | No significant | Present |
Differential diagnoses
| Hyperplastic Polyp[4] | Tubular Adenoma[4] |
|---|---|
| Nu dysplasia | Dysplasia |
| Proliferative zone restricted to base | Proliferative zone starting at the surface |
| Gland lining cells mature at the surface | No surface maturation |
Colorectal adenocarcinoma (in this case, not otherwise specified).
Colorectal carcinoma (mainly adenocarcinoma) is distinguished from an adenoma (mainly tubular and ⁄or villous adenomas) mainly by invasion through the muscularis mucosae.[5]
Also, carcinoma also commonly displays:[6]
- Varying degrees of gland formation with tall columnar cells
- Frequenty desmoplasia
- Dirty necrosis, consisting of extensive central necrosis with granular eosinophilic karyorrhectic debris. Garland of cribriform glands are frequently found in their vicinity.
Tubular or villous
| Type | Risk of containing malignant cells | Histopathology | Image |
|---|---|---|---|
| Tubular adenoma | 2% at 1.5cm[7] | Over 75% of volume has tubular appearance.[8] | 
|
| Tubulovillous adenoma | 20% to 25%[9] | 25%-75% villous[8] | 
|
| Villous adenoma | 15%[10] to 40%[9] | Over 75% villous[8] | .jpg)
|
Length of villi must be at least twice the depth of the normal mucosal thickness.[2]
- Further information: Evaluation of tumors
Further workup
Dissecting pools of mucin at the base of any adenoma should be evaluated for the possibility of mucinous carcinoma.[2]
Notes
- ↑ 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
- ↑ Monica Dahlgren, Janne Malina, Anna Måsbäck, Otto Ljungberg (1997-02-13). Lilla utskärningen.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Robert V Rouse. Adenoma of the Colon and Rectum. Stanford University School of Medicine. Original posting/last update : 1/31/10, 1/19/14
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 David J. Myers; Komal Arora. Villous Adenoma. StatPearls, National Center for Biotechnology Information. Last Update: June 18, 2019.
-"This book is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/)" - ↑ 4.0 4.1 . Hyperplastic Polyp of the Colon and Rectum - Differential diagnoses. Stanford University School of Medicine. Retrieved on 2019-09-30.
- ↑ Robert V Rouse. Colorectal Adenoma Containing Invasive Adenocarcinoma. Stanford University School of Medicine.
- ↑ Robert V Rouse. Adenocarcinoma of the Colon and Rectum. Stanford University School of Medicine. Original posting/updates: 1/31/10, 7/15/11, 11/12/11
- ↑ Minhhuyen Nguyen. Polyps of the Colon and Rectum. MSD Manual. Last full review/revision June 2019
- ↑ 8.0 8.1 8.2 Bosman, F. T. (2010). WHO classification of tumours of the digestive system . Lyon: International Agency for Research on Cancer. ISBN 92-832-2432-9. OCLC 688585784.
- ↑ 9.0 9.1 Amersi, Farin; Agustin, Michelle; Ko, Clifford Y (2005). "Colorectal Cancer: Epidemiology, Risk Factors, and Health Services ". Clinics in Colon and Rectal Surgery 18 (03): 133–140. doi:. ISSN 1531-0043.
- ↑ Alnoor Ramji. Villous Adenoma Follow-up. Medscape. Updated: Oct 24, 2016
Image sources
