A rare case of gastric adenocarcinoma arising on the surface of a fundic gland polyp is reported. A 36-year-old Japanese woman was referred to our hospital for examination and treatment of a polyp that had been detected in another hospital. She did not have a history of familial adenomatous polyposis (FAP). Endoscopic examination revealed a 10-mm-diameter fundic gland polyp in the body of the stomach. The polyp had an irregular depression on its top, suggesting the presence of malignancy. Endoscopic mucosal resection was done to make a histological diagnosis. This revealed a fundic gland polyp with a tiny superficial adenocarcinoma. Atrophic changes of the gastric mucosa were mild, although Helicobacter pylori infection was positive. It is suggested that fundic gland polyps have the potential for malignant transformation.
Keywords: Adenocarcinoma; Fundic gland polyp; Helicobacter pylori.