An asymptomatic 40-years old woman had Colonoscopy because of high serum level of CEA. Colonoscopy revealed rectal polypoid lesion 10 mm in size, which endoscopic diagnosis was high grade adenoma or intramucosal carcinoma. The lesion was located lower rectum to anal canal, ESD was performed. Resected specimen showed Tubular adenoma with severe atypia in elevated lesion, and anal intraepitherial neoplasia was adjacent to adenoma. She had a history of HPV infection. We should take care AIN during examining anal canal endoscopically, especially a patient have a history of HPV infection.
