Detecting HPV in cutaneous lesions using anti-HPV antibody immunohistochemistry

Most condyloma are diagnosed clinically (without a biopsy) or histopathologically (if biopsied) without any ancillary testing. In some cases, additional confirmation of productive infection by human papillomavirus (HPV) or typing of HPV is desired, and in situ hybridization (ISH) is the most commonly used test. However, ISH is not readily available in most laboratories and only detects certain genital subtypes of HPV. The aim of this study was to evaluate the sensitivity and specificity of an anti-HPV antibody, in 25 lesions (both HPV induced and non-HPV induced) mostly from the genital region, with comparison to results with ISH and findings on hematoxylin and eosin staining. The sensitivity and specificity for the anti-HPV antibody used in this study are 90.9% and 85.7%, respectively, compared with ISH. Immunohistochemistry with this anti-HPV antibody, like ISH, was generally positive in cases showing koilocytes/koilocytotic atypia (86%). Immunohistochemical staining also detected productive infection with HPV in 23% (3 of 13) of cases without koilocytes/koilocytotic atypia. Thus, although staining is generally positive in cases with diagnostic findings of koilocytes/koilocytotic atypia in hematoxylin and eosin sections, immunohistochemistry can detect HPV in some cases without koilocytes/koilocytotic atypia.