Penile verrucous carcinoma with anaplastic transformation following radiotherapy. A case report with human papillomavirus typing and flow cytometric DNA studies.

We report a case of penile verrucous carcinoma with anaplastic transformation after radiotherapy. A 49-year-old man with penile verrucous carcinoma initially underwent excision and chemotherapy followed by radiotherapy when the carcinoma recurred locally. Twenty-four months after the completion of radiotherapy, the verrucous cancer transformed to an anaplastic spindle-cell carcinoma, which resulted in his death 10 months after diagnosis. Autopsy confirmed a huge hemorrhagic recurrent lesion and lung metastases. In situ hybridization with biotinylated DNA probes did not detect any type of human papillomavirus (HPV) (types 6/11, 16/18, and 31/33/51) in either the primary or the anaplastic tumor. Immunohistochemical HPV capsid antigens were also negative in both lesions. A flow cytometric analysis, using paraffin-embedded materials, showed a diploid DNA content in the excised verrucous carcinoma and an aneuploid content in the anaplastic tumor. This patient most likely had radiation-induced transformation of an anaplastic carcinoma. Wide excision and, if necessary, amputation, are preferred to radiotherapy.