Evaluation of the role of genital human papillomavirus in the pathogenesis of ungual squamous cell carcinoma.

Human papillomaviruses (HPV), and particularly HPV 16, have been associated with ungual squamous cell carcinoma (USCC). But their role in tumor development remains unclear. In genital carcinoma, where the oncogenic role of HPV is well established, integration of HPV DNA into the host cell genome seems to be important for malignant transformation. To clarify the issue, we have studied the physical state of HPV 16 in 3 cases of in situ USCC by the polymerase chain reaction and by in situ hybridization. HPV DNA was integrated into the human genome in 2 cases and episomal in 1 case. This particular physical state of HPV 16 in USCC, similar to those encountered in anogenital SCC, confirms the probable role of this kind of virus in the pathogenesis of USCC.