[Detection of human papillomavirus in cutaneous extragenital Bowen's disease in immunocompetent patients].

Introduction: A specific link between human papillomavirus (HPV) types 16, 18, 31, and 33 and genital carcinomas and between HPV type 5 and cutaneous extragenital carcinomas in patients with epidermodysplasia verruciformis and renal transplant has been previously found. The aim of this prospective study was to detect HPV in cases of cutaneous extragenital Bowen's disease (BD) from non-immunosuppressed patients.

Patients And Methods: Twelve cases of cutaneous extragenital BD or Bowen's carcinoma (BC), seen in the period 1994-1996 and confirmed by histologic examination, were included in the study. Tissue sections were studied by in situ hybridization with a mixture of HPV DNA probes and specific HPV DNA probes. In addition, study on fresh materiel from 1995 included: Southern blot hybridization with various usual HPV probes (6, 11, 16, 18, 31, 33, 35, 39, 42), polymerase chain reaction (PCR) with hybridization using consensus HPV probes and probes specific for HPV types 6, 11, 16, 18 and 33. In positive samples with conventional PCR, in situ PCR with probes specific for HPV types 6/11 and 16 was performed on tissue sections.

Results: In situ hybridization was negative in all the cases. Southern blot hybridization was negative in our 9 studied cases. Three cases studied by consensus PCR were positive. PCR with specific HPV probes revealed positivity on two of these cases: HPV 6 in one, and HPV 16 in another. In situ PCR was positive with a mixed 6/11 HPV probe in the third positive consensus PCR case.

Discussion: Our study revealed the presence of HPV in 3 out of 12 cases of cutaneous extragenital BD and BC. HPV type 16, found in BC of skull, was the most usually found type in the literature. HPV types 6/11, detected in 2 cases, were rarely found in cutaneous extragenital BD and BC and these results are in favor of the oncogenic effect of these virus types. In our study, in situ hybridization and Southern blot hybridization were negative in all the cases; HPV was only found in 3 cases by conventional PCR and in 1 case by in situ PCR. The low range of detection of HPV in cutaneous extragenital BD may be due to the used methods, to difficulties related to sampling and/or to a low number of copies of the HPV genoma.