Verucciform xanthoma of the penis not associated with human papillomavirus infection.

Verruciform xanthoma (VX) is a rare lesion with a predilection for oral mucosa. Only 16 cases of VX of the penis have been reported. Histologically, VX lesions in different locations are identical; however, the etiology is controversial. Previous studies have reported the presence of human papillomavirus (HPV) in VX of the skin. The purpose of this study was to determine whether HPV is a causative agent in this rare case of VX of the penis. Microscopically, the lesion demonstrated prominent verrucoid squamous hyperplasia with hyperkeratosis, parakeratosis, and acanthosis. Histiocytes, a hallmark of VX, were identified in the elongated dermal papillae. Nested polymerase chain reaction was performed on the DNA with the commonly used primer sets MY9/MY11 and GP5+/GP6+, which identify more than 40 HPV types. The results failed to identify HPV DNA in the sample, although HPV could be readily detected in genomic DNA extracted from paraffin-embedded condyloma acuminatum, a known HPV-associated lesion. Additionally, we tested a VX lesion of the palate for HPV DNA and obtained negative results. Our results indicate that VX can arise without HPV infection and suggest other possible origins may be involved.