Flashcards in CH10 - Gastrointestinal Pathology Deck (345)
What are the complications for colonic diverticula?
1. Rectal bleeding (hematochezia) 2. Diverticulitis 3. Fistula
What is diverticulitis due to?
obstructing fecal material
How does diverticulitis present?
with appendicitis-like symptoms in the left lower quadrant
What is the relationship between colonic diverticula and a fistula?
Inflamed diverticulum ruptures and attaches to a local structure.
What does the colovesicular fistula present with?
air (or stool) in urine
What is angiodysplasia?
Acquired malformation of mucosal and submucosal capillary beds
How does angiodysplasia usually arise?
in the cecum and right colon due to high wall tension
How does rupture in angiodysplasia classically present?
as hematochezia in an older adult.
What is hereditary hemorrhagic telangiectasia?
Autosomal dominant disorder resulting in thin-walled blood vessels, especially in the mouth and GI tract
What does rupture in hereditary hemorrhagic telangiectasia present as?
presents as bleeding.
What is ischemic colitis?
Ischemic damage to the colon, usually at the splenic flexure, watershed area of superior mesenteric artery (SMA)
What does ischemic cholitis present with?
postprandial pain and weight loss; infarction results in pain and bloody diarrhea.
What is irritable bowel syndrome?
Relapsing abdominal pain with bloating, flatulence, and change in bowel habits (diarrhea or constipation) that improves with defecation
What is irritable bowel syndrome classically seen in?
What is irritable bowel syndrome related to?
disturbed intestinal motility; no identifiable pathologic changes
What may improve the symptoms of irritable bowel syndrome?
Increased dietary fiber may improve symptoms.
What are colonic polyps?
Raised protrusions of colonic mucosa
What are the most common types of colonic polyps?
hyperplastic and adenomatous polyps
What are hyperplastic polyps due to?
hyperplasia of glands; classically show a serrated appearance on microscopy
What is the most common type of polyp and where does it usually arise?
Hyperplastic polyps and it usually arises in the left colon (rectosigmoid)
Can hyperplastic polyps result in cancer?
No its benign, with no malignant potential
What are adenomatous polyps due to?
neoplastic proliferation of glands
What is the 2nd most common type of colonic polyp?
Can andenomatous polyps lead to cancer?
Benign, but premalignant, it may progress to adenocarcinoma via the adenoma-carcinoma sequence
What is the adenoma-carcinoma sequence?
it describes the molecular progression from normal colonic mucosa to adenomatous polyp to carcinoma.
What is APC?
APC (adenomatous polyposis coli gene)
What do mutations in the APC lead to?
either sporadic or germline mutations increase risk for the formation of polyp.
Mutations of what leads to increased risk for polyp progression to carcinoma?
APC, k-ras and p53
How does k-ras mutation affect polyps?
leads to formation of polyp