Difference between revisions of "Gastrointestinal tract polyps"

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Gastrointestinal tract polyps (view source)

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==Traditional adenoma==
==Traditional adenoma==
:''Includes '''tubular adenoma''', '''tubulovillous adenoma''', and '''villous adenoma'''.''
:''Includes '''tubular adenoma''', '''tubulovillous adenoma''', and '''villous adenoma'''.''
 
{{Main|Traditional adenoma}}
===General===
*Most common group of ''adenomas'' in gastrointestinal tract.
*Usually arise in the context of an ''APC'' mutation.
*Many are seen in the context of [[familial adenomatous polyposis]].
 
===Microscopic===
#Nuclear changes at the surface of the mucosa - '''key feature'''.
#*Size and shape ''or'' size change:
#**Cigar-shaped (elongated) nucleus (usu. length:width > 3:1) with nuclear hyperchromasia (more blue).
#**Large round nuclei +/- vesicular appearance (clearing) -- nuclei have white space.
#*Nuclear crowding/pseudostratification - '''important'''.
#*+/-Loss of nuclear polarity (nuclei no longer on basement membrane).
#Loss/decrease of goblet cells (common).
#Cytoplasmic hyperchromasia.
 
Notes:
*Nuclear changes deep to the surface are non-neoplastic if normal appearing mucosa (with small round nuclei) is superficial to it; mucosa that is more blue and atypical deep ''and'' less blue without nuclear atypia at the surface is said to be "maturing".
**Classically, adenomatous polyps have "reverse maturation":
***The surface is more hyperchromatic (more blue).
***The base is more mature (more globlet cells, no nuclear changes -- less blue).
*[[Ampullary adenoma]]s often have less prominent pseudostratification and fine chromatin.
 
====Images====
<gallery>
Image:Tubular_adenoma_4_low_mag.jpg| Small tubular adenoma - low mag. (WC/Nephron).
Image:Tubular_adenoma_4_high_mag.jpg| Small tubular adenoma - high mag. (WC/Nephron).
Image:Tubular_adenoma_2_intermed_mag.jpg| Tubular adenoma - intermed. mag. (WC/Nephron).
Image:Tubulovillous_adenoma.jpg| Tubulovillous adenoma (WC/Nephron).
</gallery>
 
www:
*[http://www.flickr.com/photos/jian-hua_qiao_md/3984353527/in/photostream/ TA (flickr.com)].
*[http://www.flickr.com/photos/jian-hua_qiao_md/3985116686/ TA with HGD (flickr.com)].
*[http://media.daveproject.org/media/images/pathology_img/fullsize/gsraju-flat_lession_emr-path.jpeg TA with HGD (daveproject.org)].<ref>URL: [http://daveproject.org/colon-cancer-prevention-flat-lesion-and-endoscopic-mucosal-resection/2011-06-10/ http://daveproject.org/colon-cancer-prevention-flat-lesion-and-endoscopic-mucosal-resection/2011-06-10/]. Accessed on: 24 August 2012.</ref>
 
====Typing====
Subclassified as:<ref name=pbod860>{{Ref PBoD|860}}</ref>
*''Tubular adenoma'' (most common), tubular component >75%.
*''Villous adenoma'' (least common ~= 1% of (traditional) adenomas), villous component >50%.
*''Tubulovillous adenoma'' (uncommon ~5-10% of (traditional) adenomas), villous component >=25% & <=50%.
 
In other words:
*Tubular T/V >75% / <25%; Tubulovillous T/V <=75%-50% / 25%-<50%; Villous T/V <=50% / >50%.
 
Note 1:<ref name=pbod860/>
*Most villous adenomas are sessile, i.e. flat.<ref name=emed_va>URL: [http://emedicine.medscape.com/article/170283-overview http://emedicine.medscape.com/article/170283-overview].</ref>
*Tubular adenomas tend to be pedunculated, i.e. have a stalk.
*Villous adenomas have a worse prognosis and warrant closer follow-up.
*One needs only to remember the criteria for ''tubular adenomas'' and ''villous adenomas'', as tubulovillous adenomas are what is left over.
**Tubular adenomas >75% tubular, Villous adenoma >=50% villous.
*Historically, there were different definitions for tubular adenoma, tubulovillous adenoma, and villous adenomas.<ref name=emed_va/>
**Health Organization (WHO) criteria: villous adenomas >80% villous architecture.
 
Note 2:
*There is no formal definition of "villous" architecture.<ref>R. Riddell. 12 August 2011.</ref>
**''[[Onlinepathology]]'' suggests: slender finger-like projections with length-to-width ratio greater than 4.
 
Note 3:
*The term ''tubular adenoma'' is used in different contexts; it should not be confused with [[Sertoli cell nodule]] ([[AKA]] ''testicular tubular adenoma'').
 
====Grading====
Adenomas are usually graded with a two-tier system:<ref name=driman>{{cite journal | last1 = Driman | first1 = DK. | last2 = Marcus | first2 = VA. | last3 = Hilsden | first3 = RJ | last4 = Owen | first4 = DA |title=Pathologic reporting of colorectal polyps: pan-Canadian consensus guidelines |journal=Canadian Journal of Pathology |volume=4 |issue=3 |pages=81-90 |year=2012 |month= |pmid= |doi= |url= }}</ref>
 
{| class="wikitable sortable"
!Feature
!Low grade dysplasia (LGD)
!High grade dysplasia (HGD)
!Importance
|-
|Architecture
|tubular, minimal focal gland fusion acceptable
|any of the following: (gland) cribriforming, glandular budding, intraluminal papillary tufting, sheeting (of epithelium), lamina propria invasion †
|'''key feature'''
|-
|Cytology
|usu. no features of HGD
|any of the following: loss of nuclear stratification, enlarged nuclei, loss of cell polarity, prominent nucleoli, open (clear) chromatin
|supportive feature, not sufficient alone for HGD
|}
 
Low power colour can be suggestive of HGD:
{| class="wikitable sortable"
!Feature
!Low grade
!High grade
|-
| Colour
| light blue
| dark blue
|}
 
Note:
*† In the colon, unlike other areas of the GI tract, invasive carcinoma is defined by neoplastic cells through the muscularis mucosae.  In all other places, e.g. small bowel, invasive carcinoma is defined by neoplastic cells through the basement membrane.
 
====Margins====
{{Main|Surgical margins}}
*Some pathologists believe it is impossible to determine margins in polypectomies.
*Others comment on what they see and then disclaim based on limitations with something like "... margin clear in plane of section."
 
====Haggitt classification====
The ''Haggitt classification'' is a [[staging]] scheme. Surgeons may ask about it 'cause a guy (who probably didn't do a lot of pathology) put it in a widely read surgery textbook.
In short:<ref>URL: [http://www.ganfyd.org/index.php?title=Haggitt_classification http://www.ganfyd.org/index.php?title=Haggitt_classification]. Accessed on: 19 March 2011.</ref><ref name=pmid4007423>{{Cite journal  | last1 = Haggitt | first1 = RC. | last2 = Glotzbach | first2 = RE. | last3 = Soffer | first3 = EE. | last4 = Wruble | first4 = LD. | title = Prognostic factors in colorectal carcinomas arising in adenomas: implications for lesions removed by endoscopic polypectomy. | journal = Gastroenterology | volume = 89 | issue = 2 | pages = 328-36 | month = Aug | year = 1985 | doi =  | PMID = 4007423 }}</ref>
*0 - intramucosal carcinoma.
*1 - in submucosa but in head of polyp.
*2 - neck of polyp.
*3 - stalk of polyp.
*4 - submucosa of the bowel wall but above muscularis propria.
It is mostly useless; most polyps do not have a discernible neck or stalk.
 
Note:
*Dr. Haggitt is known for GI pathology and his tragic demise.<ref>Rodger C. Haggitt Endowed Chair in Gastroenterology. URL: [http://depts.washington.edu/givemed/prof-chair/endowments/rodger-haggitt/ http://depts.washington.edu/givemed/prof-chair/endowments/rodger-haggitt/]. Accessed on: February 2, 2013.</ref> He was shot by a resident that was about to be fired.<ref>Two die in UW medical school shooting. seattlepi.com. URL: [http://community.seattletimes.nwsource.com/archive/?date=20000629&slug=4029355 http://community.seattletimes.nwsource.com/archive/?date=20000629&slug=4029355]. Accessed on: 4 February 2013.</ref><ref>URL: [http://www.washington.edu/alumni/columns/sept00/choices.html http://www.washington.edu/alumni/columns/sept00/choices.html]. Accessed on: 4 February 2013.</ref>
 
===Sign out===
====Tubular adenoma - negative for high-grade====
<pre>
COLONIC POLYP, SIGMOID COLON, BIOPSY:
- TUBULAR ADENOMA.
- NEGATIVE FOR HIGH-GRADE DYSPLASIA.
</pre>
 
====Tubulovillous adenoma - negative for high-grade====
<pre>
COLONIC POLYP, SIGMOID COLON, BIOPSY:
- TUBULOVILLOUS ADENOMA.
- NEGATIVE FOR HIGH-GRADE DYSPLASIA.
</pre>
 
====Villous adenoma - negative for high-grade====
<pre>
COLONIC POLYP, DESCENDING COLON, BIOPSY:
- VILLOUS ADENOMA.
- NEGATIVE FOR HIGH-GRADE DYSPLASIA.
</pre>
 
====Tubular adenoma with focal high-grade dysplasia====
<pre>
COLONIC POLYP, TRANSVERSE COLON, BIOPSY:
- TUBULAR ADENOMA WITH FOCAL HIGH-GRADE DYSPLASIA.
</pre>
 
====Tubular adenoma with high-grade dysplasia====
<pre>
COLONIC POLYP, SIGMOID COLON, BIOPSY:
- TUBULAR ADENOMA WITH HIGH-GRADE DYSPLASIA.
</pre>
 
====Invasion cannot be assessed====
<pre>
SIGMOID LESION, 25 CM, BIOPSY:
- TUBULAR ADENOMA.
- NEGATIVE FOR HIGH-GRADE DYSPLASIA, SEE COMMENT. 
 
COMMENT:
No stromal desmoplasia is identified. No definite submucosa is present; thus, the presence or absence of definite invasion cannot be assessed.
</pre>
 
====Fragment counting====
<pre>
COLONIC POLYP, TRANSVERSE COLON, BIOPSY:
- TUBULAR ADENOMA (IN 1/3 TISSUE FRAGMENTS).
- NEGATIVE FOR HIGH-GRADE DYSPLASIA.
</pre>
 
====Notes====
#"Negative for high-grade dysplasia and malignancy" is recommended in the Canadian consensus.<ref name=driman>{{cite journal | last1 = Driman | first1 = DK. | last2 = Marcus | first2 = VA. | last3 = Hilsden | first3 = RJ | last4 = Owen | first4 = DA |title=Pathologic reporting of colorectal polyps: pan-Canadian consensus guidelines |journal=Canadian Journal of Pathology |volume=4 |issue=3 |pages=81-90 |year=2012 |month= |pmid= |doi= |url= }}</ref> The reasoning for the first part is: "with low-grade dysplasia" may lead to over treatment by physicians that are not aware that all (traditional) adenomas have low-grade dysplasia.
#The phrase "negative for [...] malignancy" is also recommended in the Canadian consensus. This is not endorsed by [[onlinepathology]], as one very frequently does not get submucosa.  It is like reporting "negative for muscularis propria invasion" on a urinary bladder biopsy without muscularis propria. Further, the guidelines are inconsistent in that they do not advise "negative for dysplasia and malignancy" for [[SSA]]s.  If there is clinical suspicion of an invasive malignancy, it is useful to comment that no submucosa is present.
 
====Micro====
=====Tubular-tubulovillous interface=====
The sections shows colorectal-type mucosa with a tubule-forming epithelium that has cellular pseudostratification and enlarged hyperchromatic nuclei, from the crypt base to the luminal aspect (dysplasia). 
 
No cribriforming of glands, epithelial budding or intraluminal papillary tufting is identified.  Goblet cells are present in the dysplastic epithelium.  Dysplastic nuclei have an ellipsoid-shape and basally stratified.
 
A small number of rare finger-like epithelial projections (villi) are noted; however these appear to comprise less than 20% of the sampled tissue.  It is possible that the villous component is higher, due to sampling error; thus, this could represent a tubulovillous adenoma.
 
=====Tubulovillous adenoma=====
The sections shows colorectal-type mucosa with a tubule-forming and villous-forming epithelium that has cellular pseudostratification and enlarged hyperchromatic nuclei, from the crypt base to the luminal aspect (dysplasia).
 
No cribriforming of glands, epithelial budding or intraluminal papillary tufting is identified. Goblet cells are rare in the dysplastic epithelium. Dysplastic nuclei have an ellipsoid-shape and basally stratified.
 
The villous component is over 25% of the lesion but less than 50% of the lesion.


==Traditional serrated adenoma==
==Traditional serrated adenoma==
Michael
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