pathology 19 (883-895) pancreas Flashcards
what does the pancreas normally arise from embryologically
from the fusion of dorsal and ventral outpouchings of the foregut
what is the most common congenital anomaly of the pancreas
pancreas divisum
where does the main pancreatic duct typically join the common bile duct
just proximal to the papilla of vater
what is pancreas divisum cased by
failure of fusion of the fetal duct systems of the dorsal and ventral pancreatic primordia
what are the favored sites for ectopic pancreas
stomach and duodenum
what are most proenzymes from the pancreas activated by
trypsin
what is trypsin activated by
duodenal enteropeptidase (enterokinase)
what is acute pancreatitis characterized by
reversible pancreatic parenchymal injury associated with inflammation
what does acute pancreatitis result from
inappropriate release and activation of pancreatic enzymes, which destroy pancreatic tissue and elicit an acute inflammatory reaction
what are the 3 major initiating events for how inappropriate activation of pancreatic enzymes occurs in sporadic forms of acute pancreatitis
pancreatic duct obstruction, primary acinar cell injury, defective intracellular transport of proenzymes within acinar cells
what is pancreatic duct obstruction most commonly caused by
gallstones and biliary sludge
what is the most common shared feature of most hereditary forms of pancreatitis
defect that increase or sustains the activity of trypsin
what are the basic morphological alterations with acute pancreatitis
microvascular leak and edema, fat necrosis, acute inflammation, destruction of pancreatic parenchyma, destruction of blood vessels and interstitial hemorrhage
in the more severe case of acute necrotizing pancreatitis, where is necrosis occuring
acing and ductal tissues as well as islets of langerhans
describe the macroscopic substance correlated with acute necrotizing pancreatitis
red-back from hemorrhage and contains interspersed foci of yellow-white, chalky fat necrosis
what is the cardinal clinical manifestation of acute pancreatitis
abdominal pain
where is the pain typically referred with acute pancreatitis
upper back and occasionally left shoulder
what lab finding is very common with acute pancreatitis
marked elevation of serum amylase
define chronic pancreatitis
prolonged inflammation of the pancreas associated with irreversible destruction of exocrine parenchyma, fibrosis, and in late stages, destruction of endocrine parenchyma
what is the most common cause of chronic pancreatitis
long-term alcohol use
what is autoimmune pancreatitis associated with
presence of IgG-4 secreting plasma cells in the pancreas
what is chronic pancreatitis morphologically characterized by
fibrosis, atrophy and dropout of acini, and variable dilation of pancreatic ducts
what is autoimmune pancreatitis characterized by
duct-centric mixed inflammatory cell infiltrate, venalities, and increased numbers of IgG4-secreting plasma cells
describe congenital pancreatic cysts
unilocular, thin-walled cysts- believed to result from anomalous development of the pancreatic ducts
what is the term for localized collections of necrotic and hemorrhagic material that are rich in pancreatic enzymes and lack an epithelial lining
pseudocysts
where are pseudocysts most commonly located
in the lesser mental sac or in the retroperitoneum between the stomach and transverse colon or between the stomach and liver
where do serous cystic neoplasms usually occur
in the tail of the pancreas
what type of cells are serous cystic neoplasms lined by and what kind of fluid is inside
glycogen-rich cuboidal cells filled with clear, thin, straw-colored fluid
do mutinous cystic neoplasms arise more in women or men
95% of the time in women
what is the major difference between serous cystic neoplasms and mutinous cystic neoplasms
mutinous can be precursors to invasive carcinomas
where do mutinous cystic neoplasms usually occur
in the tail of the pancreas
describe the fluid in mutinous cystic neoplasms
thick, tenacious mucin and lined by a columnar mucin-producing epithelium
what do intraductal papillary mutinous neoplasms (IPMNs) usually effect and where
larger ducts of the pancreas at the head of the pancreas
are IPMNs more common in women or men
men
who is solid-pseudopapillary neoplasms most commonly seen in
young women
what are solid-pseudopapillary neoplasms filled with
hemorrhagic debris
what are invasive pancreatic cancers typically arising from
pancreatic intraepithelial neoplasia
what is the most frequently altered oncogene in pancreatic cancer
KRAS
what does KRAS do
small, GTP-binding protein that normally participates in signaling events downstream of growth factor receptors with intrinsic tyrosine kinase activity
what is the most common inactivated tumor suppressor gene in pancreatic cancers
CDKN2A
what is the strongest environmental influence for developing pancreatic cancer
cigarette smoking
what is the most common location for cancers of the pancreas
in the head
what are the 2 common features of pancreatic cancer
it is highly invasive and it elicits an intense host reaction in the form of dense fibrosis
T/F: carcinomas of the body and tail of the pancreas do not impinge on the biliary tree
TRUE
what is usually the first symptoms of carcinomas of the pancreas
pain
what is the distinct microscopic appearance of pancreatoblastomas
squamous islands admixed with acing cells
