Difference between revisions of "Small intestine"

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(expand SBO)
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=Clinical=
=The segments=
==Duodenum==
{{main|Duodenum}}
The duodenum is often biopsied by gastroenterologists.
 
Common reasons for biopsy:
*Suspected giardia.
*Suspected [[celiac sprue]].
*Is this [[cancer]]?
*Looks normal... want to dot the i's and cross the t's.
 
==Jejunum==
*Uncommonly seen by pathologists. 
*May be seen in the context of a resection done for a bowel obstruction.
 
==Ileum==
*This is seen occasionally -- often in the context of IBD and more specifically [[Crohn's disease]].
*Crohn's disease (and [[ulcerative colitis]]) is discussed in the ''[[colon]]'' article.
 
=Specific conditions=
==Small bowel obstruction==
==Small bowel obstruction==
*Abbreviated ''SBO''.
*Abbreviated ''SBO''.
===General===
===General===
*Radiologic/clinical diagnosis
*Radiologic/[[clinical diagnosis]].


The usual causes of bowel obstruction (large & small) are (mnemonic) ''SHAVING'':
The usual causes of bowel obstruction (large & small) are (mnemonic) ''SHAVING'':
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In the context of bowel obstructions and IBD, pathologists often see resected [[stoma]]s (that were put in place emergently).  These specimens are usually fairly straight forward.
In the context of bowel obstructions and IBD, pathologists often see resected [[stoma]]s (that were put in place emergently).  These specimens are usually fairly straight forward.


===Gross===
*+/-Adhesions.
*+/-Bowel contorted.
*+/-Luminal narrowing +/-proximal dilation.
*+/-Serosal exudate.
**Suggestive of perforation.


=The segments=
==Microscopic==
==Duodenum==
Features:
{{main|Duodenum}}
*+/-Adhesions (serosal).
The duodenum is often biopsied by gastroenterologists.
**Dense fibrous tissue replaces the adipose tissue.
 
**+/-Increased vascularity.
Common reasons for biopsy:
*+/-Submucosal fibrosis.
*Suspected giardia.
*Suspected [[celiac sprue]].
*Is this [[cancer]]?
*Looks normal... want to dot the i's and cross the t's.


==Jejunum==
DDx:
*Uncommonly seen by pathologists. 
*Small bowel [[adenocarcinoma]] - most important differential diagnosis.
*May be seen in the context of a resection done for a bowel obstruction.
*Metastatic adenocarcinoma - classically on the serosal aspect.
 
*[[Signet ring cell carcinoma]].
==Ileum==
*This is seen occasionally -- often in the context of IBD and more specifically [[Crohn's disease]].
*Crohn's disease (and [[ulcerative colitis]]) is discussed in the ''[[colon]]'' article.
 
=Specific conditions=
==Small bowel neoplasms==
==Small bowel neoplasms==
*Adenocarcinoma - like colonic.
*Adenocarcinoma - like colonic.
Retrieved from "https://librepathology.org/wiki/Small_intestine"