Human papillomaviruses (HPV) types 6, 11, 16 and 18 infections were investigated in 18 vulvar lesions of lichen sclerosus et atrophicus (LSA) using in situ DNA hybridization and polymerase chain reaction (PCR) on formalin-fixed paraffin-embedded specimens. Four out of 18 specimens were found to be infected with HPV type 16 using the PCR technique. Interestingly, three of these four patients were in a premenopausal state. This difference proved to be the only distinguishing feature in a comparison of HPV type 16-infected patients with non-infected patients. In situ hybridization revealed no positive result in any case and PCR demonstrated no HPV-DNA type 6, 11 or 18. Patients with HPV type 16-infected lesions may be regarded as at risk of developing vulvar cancer. Therefore, long-term follow-up of this subgroup is particularly important.
