Abstract
A 57-year-old woman was endoscopically diagnosed with having a neuroendocrine tumor (NET) in the greater curvature of the middle gastric body. The tumor was single and was accompanied by ordinary atrophic gastritis. Serological examination showed anti-gastric parietal cell antibodies, and intrinsic factor antibodies were negative. We thought that the tumor was not typeINET, but the serum gastrin level was high at 740pg/ml. After laparoscopy and endoscopy cooperative surgery, pathological examination of the resected specimens revealed NET G2 (Ki-67 6.4%). Although enterochromaffin-like (ECL) cell hyperplasia was observed in the mucosa around the tumor, it did not progress to the endocrine cell micronests. The tumor was negative for gastrin staining. After Helicobacter pylori eradication therapy, her serum gastrin level decreased. As such ECL cell hyperplasia would occur by hypergastrinemia due to H. pylori infection, her final diagnosis was type III NET. This case was considered important in the differential diagnosis and treatment selection of NET.
