Detection of human papillomavirus 60 in epidermal cysts of nonpalmoplantar location

Human papillomavirus (HPV) types 57 and 60 are associated with epidermal cysts of palmoplantar location (PPECs). Recently, there was a report of HPV 60 in a wart located in a nonpalmoplantar area as a possible precursor of a nonpalmoplantar epidermal cyst (NPPEC). There has been no study that has examined the presence and frequency of HPV in ordinary NPPECs. We reviewed 63 cases of epidermal cysts, including 59 NPPECs and 4 PPECs. After routine histopathologic review, polymerase chain reaction (PCR) of extracted DNA, sequencing of PCR products, and, finally, a homology search were undertaken. As a result, 9 of 63 (14.3%) cysts, including 6 of 59 NPPECs (10.2%), showed a positive reaction on PCR. By homology search after PCR, all were demonstrated as HPV 60. For NPPECs, no variables, including some histopathologic features, are significantly related to the presence of HPV 60 in univariate or multivariate analysis (P > 0.05).