Objective: To study the pathological classification of gastric neuroendocrine tumors and its clinico-pathological significance.
Methods: Paraffin sections of totally 52 gastric neuroendocrine tumors including 42 carcinoid tumors were studied with immunohistochemical technique, which involved 9 endocrine markers of hormones antibodies and electronic microscopy for investigating the endocrine cells and the contiguous gastric mucosa of the neuroendocrine tumors.
Results: The 52 gastric neuroendocrine tumors were divided into three types: Type I, carcinoid, associated with atrophic gastritis, altogether 26 cases. Tumor extension was limited in the mucosa or submucosa, accompanying with hypergastrinemia and G cell hyperplasia. This type is consistently preceded by and associated with generalized proliferation of endocrine cells in the mucosa at fundus. Type II, carcinoid of sporadic type, totally 16 cases, not associating with hypergastrinemia, was more aggressive. Type III, Neuroendocrine carcinomas (10 cases), were highly aggressive tumors.
Conclusion: A correct identification of different types of gastric endocrine tumors is important and implicit for the treatment and prognosis of neuroendocrine tumors.