Published online Sep 26, 2021. doi: 10.12998/wjcc.v9.i27.7973
Peer-review started: February 20, 2021
First decision: May 3, 2021
Revised: May 19, 2021
Accepted: August 18, 2021
Article in press: August 18, 2021
Published online: September 26, 2021
Gastric neuroendocrine neoplasms (g-NENs) or neuroendocrine tumors are generally slow-growing tumors with increasing incidence. They arise from enterochromaffin like cells and are divided into four types according to clinical characteristic features. Type 1 and 2 are gastrin dependent, whereas type 3 and 4 are sporadic. The reason for hypergastrinemia is atrophic gastritis in type 1, and gastrin releasing tumor (gastrinoma) in type 2 g-NEN. The diagnosis of g-NENs needs histopathological investigation taken by upper gastrointestinal endoscopy. g-NENs are positively stained with chomogranin A and synaptophysin. Grading is made with mitotic index and ki-67 proliferation index on histopathological analysis. It is crucial to discriminate between types of g-NENs, because the management, treatment and prognosis differ significantly between subtypes. Treatment options for g-NENs include endoscopic resection, surgical resection with or without antrectomy, medical treatment with somatostatin analogues, netazepide or chemotherapy regimens. Follow-up without excision is another option in appropriate cases. The prognosis of type 1 and 2 g-NENs are good, whereas the prognosis of type 3 and 4 g-NENs are close to the prognosis of gastric adenocancer.
Core Tip: Gastric neuroendocrine neoplasm is an indolent tumor, which is more commonly seen with time. It has 4 subtypes with different clinical characteristics, and diagnostic management and treatment depends on subtypes. This article reviews the history of neuroendocrine tumors, the epidemiology, pathogenesis, clinical aspects and treatment options in patients with gastric neuroendocrine neoplasms.