[Diagnostic problems of virus-induced atypical squamous cell proliferations in the area of the anus and genitalia. A case report on Bowenoid papulosis].

Papillomatous proliferations of squamous epithelium of the genital and anal region termed Bowenoid Papulosis (BP) macroscopically resemble condylomata acuminata, whereas histologically they show in part severe dysplasias. Despite the similarity of these lesions to Bowen's disease they are - like condylomas - induced by papilloma viruses and may regress spontaneously. Condyloma-like but predominantly flat proliferations of squamous epithelium of the transitional zone between exocervix and endocervix, which are likewise caused by viruses and have a prognosis similar to that of BP, are even more problematic in differential diagnostic differentiation from cervical carcinoma in situ.