[Chronic atrophic gastritis with carcinoid tumor and microcarcinoidosis. Report of a case with immunohistochemistry and ultrastructure study].

Gastric endoscopy of a 40 year old woman suffering from ill-defined epigastralgy revealed a carcinoid tumor apparently located at the mucous membrane. The tumor was neither argyrophil nor argentaffin. Immunohistochemical tests for VIP, gastrin and serotonin were negative. Biological examinations indicated hypochrome anemia and hypergastrinemia (greater than 800 pg/ml). The excision was completed by a gastrectomy of 2/3 with a Pean anastomosis. No residual tumor was detected but the fundic mucous membrane showed considerable atrophic gastritis together with a marked hyperplasia of endocrine cells giving an aspect of microcarcinoidosis. Immunohistochemical studies showed that most of the cells produced serotonin while a few cells produced gastrin or VIP. Control biopsies of the stump showed similar hyperplasia of the endocrine cells and ultrastructural studies confirmed the polymorphism of the islets. The present observation is compared to analogous cases cited in the literature. The pathogenic mechanism possibly linked to the capacity of gastrin in stimulating endocrine cells is discussed. The prognosis in these carcinoid tumors appears to be the same as in other gastric carcinoid tumors. In particular, a recent observation (Goldman et al., 1981) illustrated their aptitude to lead to metastases.