All are true about Zollinger Ellison syndrome except -

Zollinger Ellison syndrome is a rare disorder characterised by the triad of severe peptic ulceration, gastric acid hypersecretion and a neuro-endocrine tumour (p. 678) of the pancreas or duodenum ('gastrinoma'). It probably accounts for about 0.1% of all cases of duodenal ulceration. The syndrome occurs in either sex at any age, although it is most common between 30 and 50 years of age Ref Harrison 20th edition pg 667