Composite gastric carcinoid and adenocarcinoma

The light microscopical, histochemical and ultrastructural features of an unusual gastric tumour are presented. Microscopically, the neoplasm showed the features of both a conventional carcinoid tumour and of a mucin-producing adenocarcinoma. The ultrastructural demonstration of individual cells containing both endocrine granules and mucin globules supports the view that gastric enterochromaffin cells are of endodermal origin.