早期肛門管扁平上皮癌と診断した病変に対してESDを施行した1例

抄録

Colonoscopic examination of a man in his 70s revealed a whitish polyp, 10 mm in size, at the anal canal (AC) , which was pathologically diagnosed as a squamous cell carcinoma (SCC) . Magnifying endoscopy with narrow-band imaging (ME-NBI) revealed abnormal loop vessels similar to those of early esophageal SCC. The lesion was resected en bloc by endoscopic submucosal dissection (ESD) without any serious complications. Histological examination showed that the specimen was an SCC in situ ; its vertical margin was free of tumor, although its horizontal margin was indefinable at the anal end. No additional treatment was indicated and there has been no evidence of recurrence after 15 months. Visualization of abnormal vessels by ME-NBI is promising, especially for determining the depth of tumor invasion. En bloc ESD followed by pathological examination makes possible the precise diagnosis of SCC in situ.