Pancreas, Small Bowel, and Biliary Tract pathology

Question 1

Answer 1

Acute pancreatitis; grossly appears as white, chalky enzymatic degradation of the pancreatic fat and parenchyma. On LM see enzymatic fat necrosis.

Question 2

Answer 2

Hemorrhagic pancreatitis; a fulminant form of acute pancreatitis marked by complete dissolution of the parenchyma with massive hemorrhage. Grossly the pancreas becomes bright red and microscopically parenchyma is necrotic and hemorrhagic.

Question 3

Answer 3

Normal pancreas; see small interacinar ducts (left) and Islets of Langerhans (right).

Question 4

Answer 4

Chronic pancreatitis; repeated bouts of acute pancreatitis lead to parenchymal scarring (usually sparing the Islets of Langerhans). Grossly see dilated pancreatic duct with calculi inside, as well as dense/firm/white fibrous tissue.

Question 5

Answer 5

Pancreatic pseudocyst; holes created by digestion of pancreatic tissue by enzymes; called “pseudo” bc not lined by true epithelium, but fibrin and inflammatory cells at cyst edge instead. Usually are benign but if leads to peritoneal rupture can be life-threatening.

Question 6

Answer 6

Serous cystadenoma; sponge-like benign lesions make of innumerable small cysts containing serous fluid and lined by cuboidal epithelium. Almost always seen in middle-age/older women, with a 10% rate of malignant progression.

Question 7

Answer 7

Mucinous cystadenoma; large, mucin-filled cysts with ovarian-like stroma. Seen mostly in middle-age/older women, with 10% chance of malignant progession.

Question 8

Answer 8

Pancreatic neuroendocrine tumor; aka Islet cell tumors

Bottom left = normal islet

Bottome Right= neuroendocrine tumor, usually present as discrete, well circumscribed masses filled with medium-sized cells that resemble normal islet cells. Can also be scattered multifocal lesions too (i.e. MEN1 gastrinomas).

NE tumors are functiona, associated with endocrine hormone-related sxs about 50% of the time; insulinoma, glucagonoma, etc.

Majority are malignant, but slowly progressive. Hard to predict prognosis.

Question 9

Answer 9

Pancreatic neuroendocrine tumor; on LM can stain for neurosecretory granules like insulin. on EM see granules as small, round, dark bodies in the cytoplasm.

Question 10

Answer 10

Pancreatic carcinoma; most common malignancy of pancreas is ductal adenocarcinoma; 5th leading cause of cancer death in USA (5 yr survival is <5%). Sxs include wt loss, abd pain radiating to back, jaundice, migratory thrombophlebitis (Trousseau’s syndrome).

See sharp transition from normal epithelium (yellow arrow) to dysplastic epithelium (blue arrow) marked by dark, irregular nuclei with loss of cellular polarity. This dysplasia termed “pancreatic intraepithelial neoplasia or panIN,” has multiple stages and is clinically silent.

Question 11

Answer 11

Pancreatic adenocarcinoma; grossly the lesion is hard to ID because tumor is stellate with lots of fibrous stroma that blends into background of chronic pancreatitis.

Question 12

Answer 12

Pancreatic adenocarcinoma; see “unhealthy” pancreatic duct (orange circle) with adjacent reactive stroma (blue arrow). See tumor invasion of nerve bundle (green arrow). Diffusely see a hodgepodge of atypical glandular structures.

Question 13

Answer 13

Pancreatic carcinoma aortic valve vegetations; cause of non-bacterial thrombotic endocarditis, a paraneoplastic pro-coagulative phenomenon that is a sign of advanced tumor burden.

Question 14

Answer 14

Whipple procedure; a pancreatoduodenectomy used in adenocarcinoma. Can be curative if ampulla adenocarcinoma (well confined), but with pancreatic carcinoma in generally usually does not decrease mortality.

Question 15

Answer 15

Adenocarcinoma of ampulla; an uncommon tumor that presents with jaundice/biliary obstruction and/or pancreatitis. Grossly appear as frond-like tumors seen on endoscopy. At resection see near complete blockade of the ampulla.

Question 16

Answer 16

Cholangiocarcinoma of hepatic ducts; see at convergence of R and L hepatic ducts. AKA a Klatskin tumor.

Question 17

Answer 17

Adenocarcinoma of the gallbladder; very uncommon, PSC or chronic cholangitis can predispose to.

Question 18

Answer 18

Gallbladder cholecystitis and obstruction:

A) Normal gallbladder

B) Cholelithiasis: thickened muscular walls, blunted mucosal villi, and lymphocyte-rich infiltrate

C) Dense lymphocytic infiltrate due to bile acid and stones

D) Thickening of gallbladder wall due to stones

Question 19

Answer 19

Acalculous cholecystitis; patch acute necrosis of mucosa in absence of significant inflammation. Secondary to abdominal surgery, trauma, or sepsis. Mechanism poorly understood but histologically similar to acute gastritis or pancreatitis.