Zollinger-ellison syndrome is not caused by tumors from

repeated question. Zollinger-Ellison syndrome (ZES) is caused by a non-beta islet cell, gastrin-secreting tumor of the pancreas that stimulates the acid-secreting cells of the stomach to maximal activity, with consequent gastrointestinal mucosal ulceration. ZES may occur sporadically or as pa of an autosomal dominant familial syndrome, multiple endocrine neoplasia type 1 (MEN 1). The primary tumor is usually located in the duodenum, the pancreas, and abdominal lymph nodes, but ectopic locations have also been described (eg, hea, ovary, gall bladder, liver, kidney).