Gastric carcinoids of ECL cells. Pathological and clinical analysis of eight cases.

Clinical, histological, histochemical and ultrastructural characteristics of eight cases of carcinoid tumors of the non-antral portion of the stomach are presented. Four cases with multiple polypoid lesions are accompanied by an increased level of gastrin. A normal level of gastrin was present in the other four cases with isolated tumor and a normal component of endocrine cells in the uninvolved mucosa. In the first group with multiple lesions, the histological and histochemical analysis of the endocrine cells revealed a wide range of appearances: a) "simple hyperplasia", b) "nodular hyperplasia", and c) carcinoid tumor. These aspects suggested a different pathogenesis for the carcinoid tumors of the non-antral portion of the stomach with possible therapeutical implications.