Small Bowel Pathology

Question 1

What are the microscopic findings on celiac’s disease?

Answer 1

shortening and brooding of villi
increased intraepithelial lymphocytes
increased plasma cell in the lamina propria
elongation of crypts with reversal of crypt-villous ratio

Question 2

What is the pathology visible on tissue section from Whippple’s disease?

Answer 2

lamina propria with macrophages fillled with gram positive intracellular actinomycete, variable degree of mucosal atrophy and dilated lymphatics or fat vacuoles

intestine is dilated, thickened and rigid, shaggy and edematous mucosa with white/yellow plaques

PAS stains organelles

Question 3

Describe the appearance and origin of intestinal neuroendocrine cells.

Answer 3

oval to triangular with eosinophil granular cytoplasm, of endodermal origin

Question 4

Describe the gross and microscopic pathology of neuroendocrine tumors.

Answer 4

gross: small polypoid lesion beneath mucosa, may have surface ulceration and cut surface will be bright yellow
microscopy: small uniform cells with round nuclei, characteristic salt and pepper chromatin and granular eosinophilic cytoplasm; form insular, trabecular, solid and microacinar groups

Question 5

Gastrointestinal stream tumors are believed to arise from which cell? (>75% of cases have mutation in which gene?)

Answer 5

arise from interstitial cells of Cajal, >75% cases have mutation of the gene encoding c-kit (tyrosine kinase receptor) which is respsonsive to imatinib

only 8% have mutations that activate PDGFRa

Question 6

Describe the pathological appearance of gastrointestinal stromal tumors (GIST).

Answer 6

solitary, well circumscribed fleshy masses containing, proliferation below the mucosa spindle or epithiloid cell, vacuolated cytoplasm that stain positive for c-kit or CD34

Question 7

T/F Acute Pancreatitis is reversible pancreatic injury associated with inflammation.

Answer 7

true, acute pancreatitis is reversible, chronic pancreatitis is irreversible damage

Question 8

What are the microscopic findings in acute pancreatitis?

Answer 8

edema, vascular congestion, fat necrosis (enzymatic digestion- suponification), coagulative necrosis and inflammatory in filtrate and hemorrhage

Question 9

Stimulation of pancreatic ____ cells leads to fibrosis leaving the overall pancreas ______ and ____.

Answer 9

pancreatic stellate cells, pancreas appears shrunken and firm (microscopically fibrosis, loss of acini and islets)

Question 10

What is the pancreatic adenocarcinoma pre-cursor lesion?

Answer 10

pancreatic intraepithelial neoplasia, mostly in the head of the pancreas

Question 11

Describe the pathological changes in pancreatic adenocarcinoma.

Answer 11

microscopically: loss of lobular architecture with angulated glands, marked nuclear pleomorphism, perinural or lymphovascular invasion, associated with demo plastic reaction

usually a firm stellate white, poorly defined mass