GI: Colon

Colon

Colonic manifestations of various diseases

	Colonoscopy findings	Bx
Adenocarcinoma	a protuberant mass	Dysplastic mucosal cells with variable degree of gland formation
CMV	Multiple ulcers and mucosal erosions	Cytomegalic cells with inclusion bodies
Cryptosporidium	Nonulcerative inflammation	Basophilic clusters seen on the surface of intestinal mucosal cells
Entamoeba histolytica	Numerous discrete, flask-shaped ulcerative lesions	Trophozoites containing red blood cells
Kaposi’s sarcoma	Reddish/violet, flat maculopapular lesions or hemorrhagic nodules	Spindle-shaped tumor cells with small-vessel proliferation
Ulcerative colitis	Contiguous area of erythematous, friable, granular mucosa w/ possible pseudopolyps	Inflammatory infiltrate involving the mucosa and submucosa with crypt abscesses

Diverticulosis

§ Abx? Ciprofloxacin +
Metro

§ NPO for infxn

§ Surgery if? Perforation,
fistula formation, abscess, strictures, or obstruction

Cancer

COLON CA

·
family history

·
IBD

·
colorectal polyps

·
low fiber, high
fat diet (now controversial)

·
diet low in
vitamin A, E, C, and selenium

S/S

Ⓡ

Ⓛ

·
typically shows up with anemia (hypochromic, iron
deficiency)

·
the right age group (elderly), for no good reason.

·
Stools will be 4+ for occult blood.

·
Colonoscopy and biopsies are diagnostic;

·
surgery (right hemicolectomy) is treatment of choice.

·
typically shows with bloody bowel movements. Blood coats the
outside of the stool,

·
there may be constipation,

·
stools may have narrow caliber.

·
Flexible
proctosigmoidoscopic exam (45 or 60 cm) and biopsies are
usually the first diagnostic study.

·
Before surgery is done, full colonoscopy is needed to rule out
synchronous second primary.

·
CT scan helps assess operability and extent.

·
Pre-op chemotherapy and radiation may be needed for large rectal
cancers.

·
Colonoscopy + Bx

·
Evaluate for mets
w/ CT

Classification	Description	5y survival
Duke A	Tumor limited to mucosa or submucosa (mus. propia)	80%
Duke B1	Tumor invades but not through muscle wall	60%
Duke B2	Tumor penetrates entire wall but no node involvement.	55%
Duke C1	Tumor into but not through wall but positive lymph nodes	30%
Duke D	Distant metastasis regardless of invasion	<5%

Resection

PPx

PREVENT COLON CA?

If there is Aspirin in the choices choose it, then
choose fiber,
then go with vitamin
D.

Prog

Regardless of stage, the overall five year survival is
35%

	Polyps
Features	· neoplastic · most commonly adenomas · tubular – smallest malignant potential o usually pedunculated · tubulovillous – usually pedunculated · villous adenoma – greatest malignant potential o usually sessile
S/S	Most are Asx
Dx	Sigmoidoscopy / Colonoscopy
Tx	· Colonoscopic polypectomy · If you find cancer ONLY in polyp, then resect the polyp only
DDx

	Colovesical Fistula
Causes	· Diverticular disease (sigmoid most common) · Crohn disease · Malignancy (colon, bladder, pelvic organs)
S/S	· Pneumaturia (air in urine) · Fecaluria (stool in urine) · Recurrent urinary tract infections (mixed flora)
Dx	· Abdominal CT with oral or rectal (*not IV) contrast · Colonoscopy to r/o colonic malignancy*

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