Gastric endocrine cell proliferation and fundic argyrophil carcinoid tumors in patients with the Zollinger-Ellison syndrome.

The Zollinger-Ellison syndrome (ZES) is characterized by hyperchlorhydria due to sustained hypergastrinemia of tumoral origin. In ZES, as in all pathological and experimental conditions associated with chronic hypergastrinemia, endocrine argyrophil cells, particularly enterochromaffin-like cells, proliferate in the fundic mucosa. In patients with ZES, fundic argyrophil carcinoids only develop in those patients who also have multiple endocrine neoplasia type 1. The authors review factors which might influence fundic argyrophil cell proliferation in the ZES. Clinical characteristics of the patients with fundic argyrophil carcinoid tumors as well as pathology and the putative mechanisms of development of these tumors are described.