A gastrinoma is a functionally active and usually malignant endocrine tumour with clinical symptoms due to inappropriate secretion of gastrin (Zollinger Ellison syndrome; ZES)
Solcia E, Capella C, Kloppel G
. Two types of gastrinomas can be distinguished, sporadic, non-familial gastrinoma with ZES (≈80% of cases), and familial gastrinoma with ZES in the setting of MEN 1 (≈20%).
Tumors of the Pancreas
Armed Forces Institute of Pathology: Washington 1997
Gastrinomas are relatively common functionally active endocrine tumour of the pancreas accounting for about 20% of cases, second in frequency only to insulinomas
Kloppel G, Heitz PU
Churchill Livingstone: Edinburgh/New York 1984
The etiology and pathogenesis of sporadic gastrinomas are unknown.
Most patients with gastrinomas suffer from typical duodenal ulcer at presentation.
Gastrinomas show a high risk of malignant behaviour independent of size and should therefore be classified as tumours with uncertain behaviour or as well-differentiated endocrine carcinomas when gross invasion and/or metastases are present
Ronald A. DeLellis, Ricardo V. Lloyd, Philipp U. Heitz, Charis Eng
World Health Organization Classification of Tumours. Pathology and Genetics of Tumors of Endocrine Organs
IARC Press: Lyon 2004
Commentary: Neuroendocrine tumours of the digestive system