2016 Volume 58 Issue 11 Pages 2262-2267
A 68-year-old man had a positive fecal occult blood test and was referred to our hospital for examination. Colonoscopy revealed multiple polyps and diverticula from the descending colon through the sigmoid colon. The patient underwent endoscopic mucosal resection (EMR) of eight lesions. Two of these lesions were found to be early colorectal carcinomas. One of the malignancies was a 20-mm early carcinoma in the sigmoid colon, which was mainly tub2 and partly undifferentiated. The margin was clear, but the tumor extended close to the margin. Regarding the other carcinoma, the extent of infiltration was unclear because of partial resection. Based on these findings, additional resection of the two cancerous lesions was recommended, and laparoscopic D1 lymph node dissection was performed. Although no residual tumor was detected at the sites of scarring after EMR, three cancers were found inside diverticula included in the resected specimen. One of these tumors had infiltrated the subserosa and metastasized to a lymph node (no. 241), leading to the diagnosis of T3N1M0 cancer (stage Ⅲb). The patient received adjuvant chemotherapy and is currently being followed up. Colorectal cancer rarely arises in the mucosa of a diverticulum, and no case of multiple diverticular cancers has been previously reported.
Here we report a patient with multiple colorectal cancers arising in diverticula, which could not be detected by preoperative colonoscopy.
