Endoscopic Mucosal Resection for Treatment of Multiple Early Gastric Cancer Complicating Familial Adenomatous Polyposis: A Case Report

Familial Adenomatous Polyposis (FAP) is a hereditary colorectal disorder characterized by multiple adenomas developing diffusely throughout the large intestine that frequently show malignant transformation even at a young age. In a 69-year-old woman who had undergone total colectomy for FAP, endoscopic surveillance for multiple gastric polyps revealed a pedunculated polyp measuring more than 2 cm in diameter in the fornix of the stomach? As histopathological examination revealed that the polyp was an adenocarcinoma, Endoscopic Mucosal Resection (EMR) was performed to remove this polyp and three 1cm polyps around it. All the lesions were histopathologically diagnosed to be adenocarcinomas, and the risk of the remaining multiple gastric polyps progressing to cancer was also determined to be high. Therefore, total gastrectomy was performed. Histopathology of the total-gastrectomy specimen showed multiple intramucosal carcinomas. At present, there are no established guidelines for either surveillance or treatment of gastric lesions in FAP patients. As exemplified by our case, there are lesions among gastric polyps that are difficult to diagnose as cancer based on the endoscopic findings alone. For surveillance in FAP patients with multiple gastric polyps, step biopsy as well as target biopsy may need to be performed.