A case of human papillomavirus 66-associated inguinal Bowenoid papulosis

Abstract

A 75-year-old man, with a five-year history of rheumatoid arthritis and interstitial pneumonia treated using predonisolone and tacrolimus, presented with a chief complaint of a red nodule in the right groin, which appeared three months ago. Clinically, the lesion showed a red sharply marginated nodule measuring 1 cm. It presented a wet surface without scaling. Dermoscopic examination showed irregular papillomatous projections in the nodule. Histopathology of the biopsy specimen showed papillomatous lesions, hyperkeratosis, acanthosis, and atypical keratinocytes with obvious pleomorphism in the entire epidermis without vacuolated koilocytes. Atypical keratinocyte invasion into the dermis was not observed. Immunohistochemistry staining showed p16 positivity in the nucleus and cytoplasm of atypical keratinocytes. It was diagnosed as Bowenoid papulosis and a total excision with 5 mm margin was performed according to guidelines for cutaneous squamous cell carcinoma (SCC). No recurrence has been observed for 2 years. Human papillomavirus (HPV 66) was detected in the excision lesion using the HPV DNA PCR (SRL, Nagoya Japan). Some HPV types are confirmed to be carcinogenic in humans, causing mucosal lesions in cervical, penis, anal, and oropharyngeal cancers. To our knowledge, HPV 66, a probable high-risk mucosal HPV, was detected only in one case of SCC in the ungual and periungual area. Ungual and periungual SCC are well known and sometimes indicate sexually transmitted diseases. These studies suggest the possibility that mucosal high-risk HPV types in cervical cancer might also be risk factors for SCCs. Recently, HPV vaccines have been used globally. Although they do not prevent infection with most of the HPV types currently, but it is expected to spread in Japan.