Human papillomavirus 25-related DNA in solitary keratoacanthoma

Solitary keratoacanthomas of 32 patients were screened for the presence of human papillomavirus (HPV) 25 DNA, which was originally isolated and molecularly cloned from warts of an epidermodysplasia verruciformis (Ev) patient. Biotinylated virus DNA was hybridized in situ to thin sections obtained from paraffin-embedded material. HPV DNA was detected in 12 of 32 tumors under stringent conditions, and in 2 additional tumors under relaxed conditions.