The First Case of Gastric Neuroendocrine Tumors Induced by a Proton Pump Inhibitor in von Hippel-Lindau Disease

Von Hippel-Lindau (VHL) disease is a rare inherited familial syndrome complicated with various neoplasms, including neuroendocrine tumors (NETs). We herein report the first case of multiple gastric NETs in a 45-year-old man with VHL. He had multiple gastric polyps, and several endoscopic resected lesions were diagnosed as NETs. The serum gastrin level was elevated because he was taking a proton pump inhibitor (PPI). We suspected that gastrin had played a role in the development of NETs, and the remaining polyps were followed up with discontinuation of the PPI. The NETs gradually reduced in size until they became hard to notice on endoscopy and have remained nearly invisible for over eight years.