Premalignant Conditions of the Anus

The diagnosis of premalignant conditions of the anus remains a challenge, in particular differentiating between lesions which have a malignant potential and those which are of no concern. The use of anal cytology and high-resolution anoscopy (HRA) has helped to diagnose clinically suspicious lesions. In addition, HRA allows biopsy and treatment of clinically suspicious lesions. These investigations can be used to screen high-risk patients, such as HIV-positive men who have sex with men. The human papillomavirus is implicated in the aetiology of many premalignant lesions, and vaccination against it in at-risk populations may reduce the prevalence of these lesions.