Argyrophil cells in gastrointestinal epithelial tumours of the dog.

Fifty-two cases of gastrointestinal mucosal tumours of the dog were examined for argyrophil cells by means of the Grimelius stain. Argyrophil cells were found in each of five cases (100 per cent) of gastric adenoma, in five (71.4 per cent) of seven large-intestine adenomas, in 13 (59.1 per cent) of 22 gastric carcinomas, in five (62.5 per cent) of eight small-intestine carcinomas and in four (40 per cent) of ten large-intestine carcinomas. The argyrophil cells represented a minority of the tumour cell population in all cases. These results demonstrate that a significant proportion of gastrointestinal mucosal tumours of the dog contain a mixture of epithelial and endocrine cells. Similar findings have been reported in man.