Microscopic Anal Canal Adenocarcinoma with Pagetoid Spread-A Case Report

The patient is a 70-year-old woman who presented with a chief presentation of anal itching. Her previous physician diagnosed her with perianal extramammary Paget's disease, and she was referred to our hospital. Physical examination revealed a well-circumscribed red skin rash 6 cm in diameter centered on her anus. An anal skin biopsy showed adenocarcinoma, and immunostaining demonstrated CK7+,CK19+,CK20+,CDX2+, leading to the suspicion of pagetoid spread of anal adenocarcinoma. Lower gastrointestinal endoscopy revealed no obvious lesions; however, based on immunostaining results, she was diagnosed with small anal adenocarcinoma with Pagetoid spread. She underwent laparoscopic abdominoperineal rectal amputation(D1LD0)considering the circumferential circumference and possibility of a cure. A 1 cm margin of anal skin was removed, and pathological examination revealed an area filled with Paget cells in the duct near the transitional epithelium, which was considered the primary tumor and was diagnosed as anal adenocarcinoma(PE, pTisN0M0, pStage 0). The patient remains alive without recurrence for 6 months.