Endocrine cell proliferation and carcinoid development: a review of new aspects of hypergastrinaemic atrophic gastritis.

The accumulating evidence of an association between antrum-sparing hypergastrinaemic atrophic gastritis, frequently associated with pernicious anaemia, and the occurrence of gastric carcinoid tumours is briefly reviewed. The development of argyrophil cell carcinoid tumours in the atrophic fundic mucosa seems to be related to argyrophil cell hyperplasia caused by hypergastrinaemia. Epidemiologic considerations indicate that the gastric carcinoid generally is underdiagnosed and that the incidence of this tumour is higher than previously recognized. The clinical relevance of minute gastric carcinoids, or endocrine cell 'adenomas', is obscure. However, larger tumours should be regarded as potentially malignant. These findings are relevant to the aspect of long-term medically induced achlorhydria leading to hypergastrinaemia.