A unique verrucous anogenital tumor associated with type 6b-related human papillomavirus

Multiple dark brown papillomatous tumors, showing some histological features of verrucous carcinoma or giant condyloma, developed mainly in the anogenital region of a Japanese woman. The tumors first appeared when she was 51 years old and annoyed her for over 20 years with several recurrences without any frank malignant transformation, after surgery. Immunohistochemically, papillomavirus genus-specific antigen was demonstrated only in small foci of the lesions resected at first operation. Southern blot analysis revealed human papillomavirus type 6b-related DNA in a surgically resected specimen. The possible role of the human papillomavirus in the genesis of this unique tumor is discussed.