pancreas Flashcards
List 5 causes of acute pancreatitis
metabolic (alcohol, hypercalcemia) mechanical (gallstones, trauma) genetic (mutations in cationic trypsinogen PRSS1 and trypsin inhibitor SPINK1 genes vascular: vasculitis, shock infection: mumps
LIst 3 gross features of acute pancreatitis
- edema - hemorrhage - necrosis of pancreatic parenchyma and peripancreatic fat
List 3 mechanisms that can cause activation of pancreatic proenzymes
- Obstruction of pancreatic duct (gallstones, alcohol induced thick secretions) - Acinar injury; may be chemical (etoh), infection (cmv, mumps), mechanical (trauma) - Metabolic activation of proenzymes (hypercalcemia)
List pancreatic proenzyes activated by trypsin that contribute to damage in pancreatitis
- Phospholipase and lipase (fat necrosis) - Elastase: damages vessel walls (hemorrhage) - Proteinase: acinar damage - Kallikrein: activates Factor XII of clotting cascade and complement cascade (small vessel thrombosis)
Describe pathogenesis of autodigestion of pancreas by innappropriately activated pancreatic enzymes
pancreatic duct obstruction, primary acinar injury, defective intracellular transport–>activation of trypsin–>activation of prozenzymes: phospholipase/lipase, elastase, proteinase, kallikrein
List 5 complications of acute pancreatitis
- Chronic pancreatitis - Medical emergency: DIC, ARDS, shock, ATN - Diffuse fat necrosis, hypocalcemia - Pancreatic abcess or pseudocyst - Exocrine/endocrine insufficiency
List 3 histologic findings of autoimmune pancreatitis
- Duct centric lymphoplasmacytic infiltration and peridutal fibrosis - Perivenulitis and obliterative thrombophlebitis - Increased numbers of IgG4+ plasma cells
LIst 3 sequelae of chronic pancreatitis
- Pancreatic insufficiency and diabetes mellitus - chronic pain - pancreatic pseudocysts
List 3 gross findings in chronic pancreatitis
- Irregular scar - Dilated pancreatic duct with secretions and calcifications - Pseudocysts and autodigestive fat necrosis in adjacent fat
List 4 histologic features of chronic pancreatitis
- Acinar atrophy - Fibrosis - Irregular, distorted ducts - Pseudoincrease in islets (due to atrophy)
What features differentiate chronic pancreatitis from pancreatic carcinoma?
Chronic pancreatitis: - diffuse, segmental or focal; irregular scar w/secretions, pseudocytst and fat necrosis; partial preservation of lobular architecture, dilated ducts w/ calcifications, ductal epithelium with atrophy, metaplasia but no dysplasia, acinar atrophy with prominent islets, patchy fibrosis without glands, chronic inflammatory cells, no vascular or perineural invasion Ductal adenocarcinoma: - localized, usually head of pancreas; hard, solitary poorly demarcated mass without pseudocysts, fat necrosis and may have dilated duct; no lobular architecture, irregular neoplastic glands lined by dysplastic cells, necrotic cells, no acinar atrophy or prominent ilsets, desmoplastic stroma without inflammation, perineural/vascular invasion
Name the most common mutated oncogene and the most frequently inactivated tumor suppressor gene in pancreatic carcinoma
KRAS: most commonly mutated oncogene p16: more frequently inactivated tumor suppressor gene
Name the precursor lesion for pancreatic adenocarcinoma
- Pancreatic intraepithelial neoplasia (PanIN)
List 2 hereditary familial syndrome associated with pancreatic adenocarcinoma
- Hereditary pancreatitis - Peutz-Jeghers
List cystic neoplasms of pancreas and demographic associations
- Serous cystadenoma: F>M (2:1), 60-70yrs - Mucinous cystadenoma: F (95%) - Intraductal papillary mucinous neoplasm: M>F - Solid pseudopapillary neoplasm: young F
List the clinicopathological features used to differentiate IPMN, mucinous cystic neoplasm, serous cystadenoma
IPMN: 50-75 yrs, men, hx pancreatitis, bulging papillae into duodenum lumen, found at head of pancreas, duct epithelium involved, usually multiple cysts, extensive papilla formation, columnar mucin producing epithelium, no ovarian stroma, adjacent pancreas normal mucinous cystic neoplasm: 40-50yrs, female, no specific history, solitary multilocated cysts, body/tail, no connection to duct, single cyst, usually minimal papillae, columnar mucinous epithelium, ovarian stroma present, atrophic pancreas serous cystadenoma: 50+yrs, usually female, no specific hx, CT honeycomb cyst, anywhere in pancreas, no relationship to duct, honeycomb cut surface, no papillae, flattened cuboidal epithelium ++glycogen, no ovarian stroma, normal pancreas
Compare/contrast features of PanIN from IPMN
PanIN: size 1cm, mucin hypersecretion, dilated duct, tall papillae with stroma core, MUC1+ in pancreatobiliary/oncocytic, MUC2+ in intestinal type, NO KRAS mutations, DPC4+, associated with colloid carcinoma
Describe the handling of a whipple specimen
- Identifiy and orient anatomical structures including distal stomach, duodenum, CBD, pancreas. Ink the specimen @ parenchymal resection margins - Open stomach along greater curvature/across anterior wall of pylorus, down outer curvature of duodenum. Record dimensions of all structures. - Sample margins: distal pancreas margin, uncinate margin, CBD, duodenum, gastric margin - using probe, cut through CBD, pancreatic duct, ampulla of vater - Identify/describe lesion: size, colour, consistency, demarcation, relationship to duodenum, CBD, portal vein, distance to margins, ductal obstruction - Photograph - Describe non-neoplastic tissue - Fix overnight in 10% formalin - Prepare blocks: 6 blocks of tumor including relationship to pancreatic/cbd, ampulla, duodenum, surrounding pancreas, margins, non-neoplastic pancreas, ampulla, all lymph nodes
List 2 pancreatic cystic tumors that are PR positive
- Solid pseudopapillary neoplasm: neoplastic epithelial cells (they are ER negative!!!) - Ovarian stroma of mucinous cystic neoplasm (ER also +)
List the criteria for defining Ampulla of Vater tumors
- Epicenter of tumor: must be within ampulla - Pre-invasive neoplasia in the ampulla of Vater