Progression From Antral G-Cell Hyperplasia to Gastric Neuroendocrine Tumor in a Patient With Autoimmune Gastritis.

Autoimmune metaplastic atrophic gastritis is caused by immune-mediated destruction of gastric parietal cells. This leads to the absence of gastric acid production, which causes compensatory hyperplasia of gastric antral G-cells leading to hypergastrinemia. The excess gastrin binds to enterochromaffin-like cells causing hyperplasia, which may progress to dysplasia and rarely to gastric neuroendocrine tumors. We present a rare case of autoimmune metaplastic atrophic gastritis associated with G-cell hyperplasia showing the full developmental spectrum of enterochromaffin-like cell proliferation from hyperplasia to dysplasia to neuroendocrine tumor.