[Primary gastric endocrine tumors].

Objective: To study the clinicopathological features of gastric neuroendocrine tumors.

Methods: Twenty cases were reviewed. The specimens were formalin-fixed, paraffin-embedded and immunostained by S-P method.

Results: Among the twenty cases, one case was carcinoid, three were malignant carcinoids, six had small cell carcinomas and ten had mixed extocrine--endocrine carcinomas. Immunohistological examination of tumor cells found 80% positive for S-100, NSE (85%), CgA (50%), SY (50%), gastrin (30%), serotonin (65%), AE1/AE3 (50%), and CEA (80%).

Conclusions: In the WHO classification, there are five histological types in endocrine tumors of gastrointestinal tract. They are carcinoid, malignant carcinoid, small cell carcinoma, mixed exocrine--endocrine carcinoma and tumor-like lesions. But some cases in our paper were so different that they could not be classified. The gastric endocrine tumors are different from intestinal endocrine tumors and in classification, treatment and prognosis.