Exploration of the gastrinoma triangle

Gastrin-secreting neoplasms were first described by Zollinger and Ellison in 1955. These unusual neoplasms can be either benign or malignant. The diagnosis of the Zollinger-Ellison syndrome depends on an increased fasting serum gastrin concentration (>100pg/ml), increased basal acid output (>10mEq/l), and an abnormal secretin test (increase of >200pg/ml in serum gastrin concentration after 2U/kg of intravenous secretin). While originally believed to be primarily neoplasms of the pancreas, today we know that most curable gastrinomas arise in the wall of the proximal duodenum. Gastrinomas can occur as sporadic (non-familial) neoplasms or as one of the manifestations of multiple endocrine neoplasia-1 syndrome (MEN-1); MEN-1 includes neoplasms of the pituitary and parathyroids, neuroendocrine neoplasms of the duodenum and pancreas, and carcinoid neoplasms of the foregut and midgut.