Paraffin sections of 11 formalin-fixed trichilemmomas were investigated for the presence of human papillomavirus (HPV) DNA by the polymerase chain reaction (PCR) with the degenerated consensus primer pairs. PCRs were conducted with different annealing temperatures. When the annealing temperature was reduced from 55 degrees C to 50 degrees C, amplification products of the expected size were obtained for all 11 cases investigated. Determination of the HPV type was performed by cloning and sequencing of the amplification products. The sequence analysis of the eleven cloned amplicons gave the following data: based on sequence comparison with published amino acid sequences, the best homology was found to epidermodysplasia verruciformis (EV)-associated HPVs (supergroup B). In four specimens an HPV type 23 related type was found; five specimens contained HPV sequences which did not match with one of the known HPV types, but had the closest homology to HPV types 15, 17, and 37. Three of the HPV variants which had not been characterised, displayed identical sequences. Two additional HPV amplification fragments displayed played 100% homology to HPV-6b. These results demonstrate, for the first time, the presence of HPV DNA in trichilemmomas. The sequence data suggest that HPV variants or types in trichilemmoma are members of the EV-associated HPV supergroup B.

Trichilemmomas are not associated with human papillomavirus DNA. J Cutan Pathol. 1991 Jun;18(3):193-7.

Trichilemmoma is considered a benign neoplasm derived from the outer root sheath of the hair follicle. Although the histogenesis of the lesion is unknown, a relationship between human papillomavirus (HPV) infection and development of these tumors has been suggested on morphologic observations. In order to determine whether HPV is, in fact, present in these lesions, we have analyzed sections from 25 formalin-fixed, paraffin-embedded trichilemmomas for the presence of occult HPV DNA using ultrasensitive DNA amplification technology. Under carefully controlled conditions normally effective in detecting HPV from condyloma or verrucae, we were unable to detect an HPV-induced amplimer in agarose gels or their corresponding Southern blots using radiolabeled probes. Our results do not support the hypothesis that trichilemmomas arise from HPV infection.