Narrowband imaging colonoscopy with a transparent hood for diagnosis of a squamous cell carcinoma in situ in the anal canal

Abstract

Anal cancer is a relatively rare malignancy [1]. An analysis of the National Cancer Data Base showed that most patients with anal carcinoma (71.1 %) required invasive treatments such as chemoradiation therapy with or without surgery, and the 5-year overall survival for these patients was 58.0 % [2]. Anal squamous cell carcinoma in situ (CIS) accounts for almost 10 % of all anal carcinomas [3]. Here we present a case of anal canal squamous cell CIS incidentally detected in a patient at low risk of developing anal cancer. The presence, histology, and spread and depth invasion of the tumor were correctly diagnosed by narrowband imaging (NBI) with magnification.