A 50-mm rectal tumor treated by en bloc endoscopic mucosal resection

Abstract

A 62-year-old man underwent barium enema examination because of a positive occult blood test. It revealed a rectal tumor, so he was admitted to our hospital for treatment. Colonoscopy showed a large elevated tumor, measuring 50mm in size, and endoscopic ultrasonography (EUS) demonstrated that the tumor did not invade the submucosa. Endoscopic mucosal resection (EMR) was performed using an electro-surgical snare (thin type) because strip biopsy was associated with a high risk of piecemeal resection due to the location and size of the tumor. The lesion was resected en bloc by EMR. Histological examination showed a well differentiated adenocarcinoma-in-adenoma with minute invasion of the submucosa. The margin of the specimen was free of tumor invasion along its circumference. Thus, the lesion fulfilled the criteria for curative EMR. This procedure seems to be useful for en bloc resection of relativery large colorectal tumors.