Difference between revisions of "Colon"

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(→‎Angiodysplasia: +microscopic)
(move stoma to top, subdivide)
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An introduction to gastrointestinal pathology is found in the ''[[gastrointestinal pathology]]'' article.
An introduction to gastrointestinal pathology is found in the ''[[gastrointestinal pathology]]'' article.


==Surgery==
=Clinical problems=
Introduction to colorectal surgery:
# Colonic resection - remove a piece of large bowel.
# Total colectomy - leaves rectum and anus.<ref>[http://www.allaboutbowelsurgery.com/shared/stoma_care/stoma_surgery/procedures/surgery_colon/subtotal.htm http://www.allaboutbowelsurgery.com/shared/stoma_care/stoma_surgery/procedures/surgery_colon/subtotal.htm]</ref>
# Subtotal colectomy - part of colon removed --or-- some of the rectum remains.
# Right hemicolectomy - right colon + distal ileum.
# Lower anterior resection (LAR) - proximal rectum +/- sigmoid (for proximal rectal malignancies).
#* Specimens have should have intact mesorectum - ''total mesorectal excision'' (TME) - reduces local recurrence.<ref name=pmid8665198>{{Cite journal  | last1 = Arbman | first1 = G. | last2 = Nilsson | first2 = E. | last3 = Hallböök | first3 = O. | last4 = Sjödahl | first4 = R. | title = Local recurrence following total mesorectal excision for rectal cancer. | journal = Br J Surg | volume = 83 | issue = 3 | pages = 375-9 | month = Mar | year = 1996 | doi =  | PMID = 8665198 }}</ref>
# Abdominoperineal resection (APR) - anus + rectum - results in a permanent stoma (for distal rectal malignancies).
 
==Grossing==
===Identifying the piece===
*Transverse colon - has omentum.
*Ascending colon - usu. comes with ileocecal valve and a bit of ileum.
*Descending colon - has a bare area.
*Rectum - has adventitia. (???)
 
===Lymph nodes===
*One should get at least 12 [[lymph nodes]] if it is cancer.<ref name=pmid18780863>{{cite journal |author=Bilimoria KY, Bentrem DJ, Stewart AK, ''et al.'' |title=Lymph node evaluation as a colon cancer quality measure: a national hospital report card |journal=J. Natl. Cancer Inst. |volume=100 |issue=18 |pages=1310–7 |year=2008 |month=September |pmid=18780863 |doi=10.1093/jnci/djn293 |url=http://www.medscape.com/viewarticle/581463}}</ref>
 
===Quirke method===
*Bowel is not opened - it is fixed... then sliced.<ref name=pmid18667357>{{cite journal |author=West NP, Morris EJ, Rotimi O, Cairns A, Finan PJ, Quirke P |title=Pathology grading of colon cancer surgical resection and its association with survival: a retrospective observational study |journal=Lancet Oncol. |volume=9 |issue=9 |pages=857–65 |year=2008 |month=September |pmid=18667357 |doi=10.1016/S1470-2045(08)70181-5 |url=}}</ref>, <ref name=pmid18541901>{{cite journal |author=West NP, Finan PJ, Anderin C, Lindholm J, Holm T, Quirke P |title=Evidence of the oncologic superiority of cylindrical abdominoperineal excision for low rectal cancer |journal=J. Clin. Oncol. |volume=26 |issue=21 |pages=3517–22 |year=2008 |month=July |pmid=18541901 |doi=10.1200/JCO.2007.14.5961 |url=}}</ref>.
 
===Standard method===
*Bowel is prep'ed by opening it along the antimesenteric side.
*Dimensions - length, circumference at both margins.
*Radial margin/circumferential margin - should be painted.
**Rectum starts/sigmoid ends @ place where serosa ends on the posterior aspect of the bowel.
***The proximal, anterior aspect of the rectum has serosa, i.e. it is not painted.
 
==Common clinical problems==
===Obstruction===
===Obstruction===
Top three (in adults):<ref>URL: [http://www.emedicine.com/EMERG/topic65.htm http://www.emedicine.com/EMERG/topic65.htm]. Accessed on: 28 June 2011.</ref>
Top three (in adults):<ref>URL: [http://www.emedicine.com/EMERG/topic65.htm http://www.emedicine.com/EMERG/topic65.htm]. Accessed on: 28 June 2011.</ref>
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****[http://commons.wikimedia.org/w/index.php?title=File:CMV_colitis_-_intermed_mag.jpg CMV colitis - intermed. mag. (WC)].
****[http://commons.wikimedia.org/w/index.php?title=File:CMV_colitis_-_intermed_mag.jpg CMV colitis - intermed. mag. (WC)].


=Grossing=
==Types of specimens==
Introduction to colorectal surgery:
# Colonic resection - remove a piece of large bowel.
# Total colectomy - leaves rectum and anus.<ref>[http://www.allaboutbowelsurgery.com/shared/stoma_care/stoma_surgery/procedures/surgery_colon/subtotal.htm http://www.allaboutbowelsurgery.com/shared/stoma_care/stoma_surgery/procedures/surgery_colon/subtotal.htm]</ref>
# Subtotal colectomy - part of colon removed --or-- some of the rectum remains.
# Right hemicolectomy - right colon + distal ileum.
# Lower anterior resection (LAR) - proximal rectum +/- sigmoid (for proximal rectal malignancies).
#* Specimens have should have intact mesorectum - ''total mesorectal excision'' (TME) - reduces local recurrence.<ref name=pmid8665198>{{Cite journal  | last1 = Arbman | first1 = G. | last2 = Nilsson | first2 = E. | last3 = Hallböök | first3 = O. | last4 = Sjödahl | first4 = R. | title = Local recurrence following total mesorectal excision for rectal cancer. | journal = Br J Surg | volume = 83 | issue = 3 | pages = 375-9 | month = Mar | year = 1996 | doi =  | PMID = 8665198 }}</ref>
# Abdominoperineal resection (APR) - anus + rectum - results in a permanent stoma (for distal rectal malignancies).
# [[Stoma]] - these are often done emergently and then get cut-out after the patient's condition has settled.
===Identifying the piece===
*Transverse colon - has omentum.
*Ascending colon - usu. comes with ileocecal valve and a bit of ileum.
*Descending colon - has a bare area.
*Rectum - has adventitia. (???)
===Lymph nodes===
*One should get at least 12 [[lymph nodes]] if it is cancer.<ref name=pmid18780863>{{cite journal |author=Bilimoria KY, Bentrem DJ, Stewart AK, ''et al.'' |title=Lymph node evaluation as a colon cancer quality measure: a national hospital report card |journal=J. Natl. Cancer Inst. |volume=100 |issue=18 |pages=1310–7 |year=2008 |month=September |pmid=18780863 |doi=10.1093/jnci/djn293 |url=http://www.medscape.com/viewarticle/581463}}</ref>
===Quirke method===
*Bowel is not opened - it is fixed... then sliced.<ref name=pmid18667357>{{cite journal |author=West NP, Morris EJ, Rotimi O, Cairns A, Finan PJ, Quirke P |title=Pathology grading of colon cancer surgical resection and its association with survival: a retrospective observational study |journal=Lancet Oncol. |volume=9 |issue=9 |pages=857–65 |year=2008 |month=September |pmid=18667357 |doi=10.1016/S1470-2045(08)70181-5 |url=}}</ref>, <ref name=pmid18541901>{{cite journal |author=West NP, Finan PJ, Anderin C, Lindholm J, Holm T, Quirke P |title=Evidence of the oncologic superiority of cylindrical abdominoperineal excision for low rectal cancer |journal=J. Clin. Oncol. |volume=26 |issue=21 |pages=3517–22 |year=2008 |month=July |pmid=18541901 |doi=10.1200/JCO.2007.14.5961 |url=}}</ref>.
===Standard method===
*Bowel is prep'ed by opening it along the antimesenteric side.
*Dimensions - length, circumference at both margins.
*Radial margin/circumferential margin - should be painted.
**Rectum starts/sigmoid ends @ place where serosa ends on the posterior aspect of the bowel.
***The proximal, anterior aspect of the rectum has serosa, i.e. it is not painted.
=Specific entities=
==Inflammatory bowel disease==
==Inflammatory bowel disease==
{{main|Inflammatory bowel disease}}
{{main|Inflammatory bowel disease}}
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==Bowel ischemia==
==Bowel ischemia==
===General===
===General===
Etiology:
*[[Atherosclerosis]].
*[[Atherosclerosis]].
*Radiation.
*Radiation.
*Infection.


===Gross===
===Gross===
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*Biphasic tumour; features of ''carcinoid tumour'' and ''adenocarcinoma''.
*Biphasic tumour; features of ''carcinoid tumour'' and ''adenocarcinoma''.


==Stoma==
=See also=
{{Main|Ditzels#Stoma}}
These are often done emergently and then get cut-out after the patient's condition has settled.
 
==See also==
*[[GIST]].
*[[GIST]].
*[[Gastrointestinal pathology]].
*[[Gastrointestinal pathology]].
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*[[Small bowel]].
*[[Small bowel]].


==References==
=References=
{{reflist|2}}
{{reflist|2}}


[[Category:Gastrointestinal pathology]]
[[Category:Gastrointestinal pathology]]