Background: It is hypothesized that trichilemmomas are 'burned out' verrucae. By performing in situ hybridization using HPV type-specific probes, we explored this concept. Methods: Verrucae vulgaris and plantaris were positive controls, and inverted follicular keratoses (IFKs) were negative controls. Additionally, all lesions were tested for HPV genital types (low and high risk). Results: We analyzed 9 trichilemmomas, 20 verrucae vulgaris, 8 verrucae plana, 3 verrucae plantaris and 6 IFKs. All trichilemmomas were negative for HPV types 1, 2 and genital types. Conversely, 9/20 verrucae vulgaris, 2 verrucae plantaris, and 1 verruca plana were positive for HPV type 2. Among HPV-2 positive lesions, 2/2 verrucae plantaris and 1 verruca vulgaris (chin) were strongly positive for genital-type HPV. One verruca plana (shin) was positive for genital-type HPV only. All 6 IFKs were HPV negative. Conclusions: Using HPV type 1 and 2-specific probes and mixed genital-type probes, we were unable to detect HPV in trichilemmomas. This suggests that HPV-1, HPV-2 and low and high risk genital-type HPVs are not involved in the histogenesis of trichilemmoma. We also showed that genital HPV types could be present in non-genital verrucae. Stierman S, Chen S, Nuovo G, Thomas J. Detection of human papillomavirus infection in trichilemmomas and verrucae using in situ hybridization.
ASJC Scopus subject areas
- Pathology and Forensic Medicine