<prompt> All of the following are true about Zollinger Ellison Syndrome except -It is due to the presence of a gastrinomaGastrin provocation tests are a part of diagnostic work upIt might be associated with ulcers in unusual locations in stomachThey may be associated with insulinomas  <response>: Ans. is d i.e., They may be associated with insulinomas Zollinger Ellison syndromeo ZES is caused by gastrin secreting gut neuroendocrine tumors gastrinomas, which result in hypergastrinemia and acid hypersecretion.o Clinical situations that create suspicion for ZES are - ulcers in unusual locations ulcers in second part of duodenum beyond ulcers refractory to standard medical therapy ulcer recurrance after acid reducing surgery ulcers presenting with frank complications bleeding, perforation and obstruction ulcers in the absence of H. pylori or NS AID ingestion. - giant ulcers 2 cm multiple duodenal ulcers ulcers associated with diarrhoea ulcer patient with hypercalcemia or family ho ulcers ulcers with severe esophagitis. ulcers associated with prominent gastric folds ulcers with findings so MEN-1 endocrinopathy, family ho ulcers or endocrinopathy, nephrolithiasisDiagnosis of ZES gastrinomao The first step in evaluation of a patient suspected of having ZES or gastrinoma is to obtain as fasting gastrin level. All gastrinoma patients have a fasting gastrin level 150 pgmL.o The next step is to assess acid secretion by measuring basal acid output BAO which should be 15 meqh normal 4 meqh A gastric pH of 3.0 implies hypochlorhydria and excludes gastrinomao Gastrin Provocative tests In a pt. with pH 2.0 or BAO 15 meqhr and fasting gastrin level 1000 pgmL, the diagnosis of ZES is confirmed. With pH 2.0 or BAO 15 meqL and lower gastrin levels 150-1000 pgmL, a secretin stimulation test is perforfmed to distinguish ZES from other causes of hypergastrinemia. A rise of 200 pgmL of serum gastrin level within 15 min of secretin injection, confirms ZES. 