Neuroendocrine carcinomas of the stomach: a clinicopathologic evaluation.

ABSTRACT

BACKGROUND: The purpose of this study was to determine by immunocytochemistry the relative incidence and clinicopathologic characteristics of neuroendocrine carcinomas of the stomach. METHODS: Sections from paraffin blocks from 81 patients who had undergone resection of carcinomas of the stomach were immunostained with a battery of neuroendocrine differentiation markers and with A-80, a marker of exocrine differentiation. The clinical and pathologic data of the 12 patients diagnosed with neuroendocrine carcinomas of the stomach were analyzed. RESULTS: The 10 men and two women ranged from 53 to 81 years of age (median, 69 years). Procedures performed included distal subtotal gastrectomy in eight patients and total gastrectomy in four patients. Pathologic stages were stage I, one patient; stage III, four patients; and stage IV, seven patients. Metastatic sites included regional nodes, 11 patients; liver, four patients; and bone, one patient. Adjunct treatment included multiagent chemotherapy plus radiotherapy, four patients; and only radiotherapy, one patient. Eleven patients died of disease 1 to 27 months after diagnosis with an overall median survival of 15 months. Three groups of neuroendocrine carcinomas were identified based on immunostaining patterns. These included pure neuroendocrine carcinomas, two patients; neuroendocrine carcinomas with occasional exocrine cells, three patients; and mixed neuroendocrine-exocrine carcinomas, seven patients. CONCLUSIONS: (1) The relative incidence of neuroendocrine differentiation in carcinomas of the stomach is higher than is generally recognized. (2) Neuroendocrine gastric carcinomas behave aggressively and display numerous structural and functional similarities with their colonic, extrahepatic biliary tract, and pulmonary counterparts.