Histopathology of gastric carcinoids: a survey of 42 cases.

An unselected series of 42 gastric carcinoids has been reviewed. Clinically the tumours simulated common gastric lesions including ulcer, polyp and carcinoma. No endocrine symptoms were identified. The tumours were most frequent in the body of the stomach and in 25% in that site were multiple. Morphologically most tumours when classified according to Soga (1974) demonstrated a mixed growth pattern. Six tumours displayed an atypical morphology (type D): they were larger and metastasized more frequently than the rest of the tumours. Six tumours contained a few scattered argentaffinic cells but the others were negative indicating negligible serotonin secretion in only a few cases. The Grimelius argyrophilic reaction was positive in most cells in all tested tumours except in three, two of which showed atypical morphology (type D). It is suggested that gastric carcinoids with a type D morphology or a minority cell population of argyrophil cells are dedifferentiated carcinoids which are biologically nearer to gastric carcinomas. The most frequent clinicopathological correlation was achlorhydria linking pernicious anaemia and gastric carcinoids. This indicates pathogenetic similarities between gastric carcinoids and gastric carcinomas.