<prompt> Zollinger Ellison syndrome is characterized byFulminating ulcer in stomach and duodenumRecurrent ulceration despite adequate therapyNon-beta islet cell tumors of the pancreasAll of the above  <response>: Endocrine causes of duodenal ulcers can be Zollinger-Ellison syndrome, MEN syndrome, hyperparathyroidism.ZOLLINGER ELLISON SYNDROME is characterised by fulminant ulcer in stomach and duodenum and its recurrences in spite of adequate therapy .they are also characterised by non-beta cell islet tumours of pancreas Ref: SRB;s manual of surgery,3 rd ed, pg no 774 