抄録
A 47-year-old male who had underwent surgical operation because of sigmoid colon carcinoma before 7 years was admitted to our hospital for follow-up examinations. Colonoscopic findings showed a small elevated lesion with a central depression in the descending colon. We tried to perform endoscopic mucosal resection for this lesion, but elevation of the tumor was not observed after submucosal saline injection. Magnifying colonoscopic findings with crystal violet staining showed type VN pit pattern in a depressed area on the tumor, and histological diagnosis of the biopsied specimen was well differentiated adenocarcinoma. Left hemicolectomy was performed. Macroscopic findings of the resected specimen showed a IIa+IIc-like lesion, measuring 6×5 mm in size.
Histological findings showed adenocarcinoma invading the subserosa accompanied by fibrosis in the submucosa and marked focal hypertrophy of the muscularis propria. No metastatic lesion was detected in the resected lymphnodes.
Advanced colorectal carcinomas less than 10mm in size are very rare. We also reported the clinicopathological characteristic of these small lesions in Japanese literatures.
