Gastric Cancers and Gastrinomas Flashcards
Key features of general gastrointestinal neuroendocrine tumors types
well differentiated-solid, trabecular, gyriform or glandular pattern, salt and pepper chromatin, granular cytoplasm
poorly differentiated-resembled small or large cell neuroendocrine lung carcinoma
What is a marker for GI neuroendocrine tumors?
Ki67-large protein involved in cell cycle regulation and/or organization of the nucleolus
increased staining-worse prognosis
Type 1 GI neuroendocrine tumor features
derived from ECL cells associated w/chronic atrophic gastritis and pernicious anemia women old small and multiple high gastrin, turns to carcinoid tumors usually indolent and benign
Type 1 GI neuroendocrine tumor tx
endoscopic resection 2cm
What is another name for GI neuroendocrine tumors?
Carcinoid tumors
Type 2 GI neuroendocrine tumor features
associated w/gastrinomas/MEN1
high gastrin levels
typically indolent
What is MEN1?
AD predisposition to tumors of the parathyroid, pituitary and enteropancreatic cells
Type 2 GI neuroendocrine tumor tx
endoscopic resection <2cm
address gastrinoma
Type 3 GI neuroendocrine tumor features
sporadic, most aggressive
hepatic or local meastases
normal serum gastrin
Type 3 GI neuroendocrine tumor tx
partial or total gastrectomy w/local lymph node resection
What is a gastrinoma? Alias?
Zollinger-Ellison syndrome
hypersecretion of gastric acid due to ecess gastrin
derived from ECL cells, a neuroendocrine tumor
designated by clinical production of gastrin, NOT morphologic appearance/gastrin staining
Gastrinoma features
sporadic
men
assoc w/MEN1 (parathyroid and pituitary adenomas)
20-50 yos
Where do gastrinomas usually arise from?
duodenum
What are the differences between duodenal and pancreatic gastrinomas?
D-small, often multiple
P-solitary, more malignant potential
Presentation for gastrinoma?
PUD
acid reflux
prominent gastric folds
diarrhea
How do you diagnose gastrinoma?
fasting serum gastrin secretin stimulation test calcium infusion study:arterial calcium gluconate infusion CT MRI Octreoscan US (most sensitive imaging modality)
What is the secretin stimulation test?
secretin stimulates the release of gastrin by gastrinoma cells, inhibits gastrin release by normal gastric G cells
What is the calcium infusion study: arterial calcium gluconate infusion?
positive study-increased serum gastrin and calcium levels
to dx gastrinoma
Tx for gastrinoma?
high dose acid suppression
surgery
metastatic disease-somastostatin analogs, liver directed therapy, chemo
Do gastrinoma patients with MEN1 have a better or worse prognosis?
lower rate of metastasis and higher survival
What is associated with gastrinoma that confers a worse prognosis?
higher fasting gastrin level