Pathology Associates Of Lexington, P.A.

Small Bowel Tumors and Polyps

The small intestine is the part of the intestinal tract in which nutrients are absorbed out of the stream of "chyme". Isolated outgrowths or protrusions extend from the various levels of the bowel wall into its internal hollow space (as with the inside of a hose), the lumen. Some are growths and some are temporary artifacts. About the only way to find asymptomatic lesions is with capsule endoscopy. Others are found when obstruction causes pain and imaging exams are made; and some are coincidentally found during various imaging exams for other reasons.

Benign Lesions:

non-tumorous, non-"growth" polyps and lesions:
- mucosal malformation "tag"...simple polyp
- enlarged normally located mucosal lymphoid nodule
- everted mucosal diverticulum
- hyperacidic duodenopathy, peptic duodenopathy: foveolar metaplasia of surface epithelium and increased volume of Brunner's gland component (if biospies deep enough to visualize) often expressed by findings of glandularity high in lamina propria [L08-13463; S09-4458]. When relatively acute & intense, the foveolar areas can undergo reactive gastropathy change [S09-4458].
- portal hypertensive duodenopathy: may see capillary congestion & angiogenesis (erythematous duodenopathy phase) & even some lamina propria edema or fibrosis.
tumors or growths, benign:
- nonspecific "simple mucosal polyp"
- Brunner's gland nodularity [S08-16296], plaques, or polyps [L08-13588 almost 2cm] of duodenum, usually in cases with chronic high acid output from stomach.
- soft tissue polyps: lipoma (duod. FA08-139); ganglioneuroma ; angiomyolipoma ; leiomyoma.
- adenomatous polyp
- carcinoid, more info here.
tumors or growths, malignant:
- carcinoma:
  - adenocarcinoma (very common):
  - small-cell carcinoma
  - medullary:
- carcinoid tumor, malignant (there are ordinary and mucinous variants) here.
- sarcoma:
  - GIST
    - specific IHC marker CD117 positive²
    - may be a tumor of the "interstitial cells of Cajal"²
    - roughly tend to be "myoid" or "neural" (GANT...gastrointestinal autonomic nerve tumor) and there are at least two classification systems: Suster and Rosai²
    - behavior differs somewhat in different GI sites¹
    - ASCO meeting in San Francisco, 13 May '01: report that Gleevec has some striking cure rates [newspaper]
    - favorable response to STI571²
  - other traditional sarcomas
- lymphoma:
  - MALT-type...low-grades arising primarily in the GI tract organ
  - those secondarily affecting GI
Other intestine-associated obstructing or mass lesions:
- diverticulum
- enterocoel: [LMC-05-1472 abscessed & interloop adhesion & obstruction]

References:

for 1 & 2

(posted 4 February 2007; latest addition 2 May 2009)