Vulvar squamous cell carcinoma and papillomaviruses: indications for two different etiologies

The vulvectomy specimens of 78 patients with vulvar squamous cell carcinoma were reviewed and examined for human papillomavirus (HPV) types 6, 11, 16, 18, and 33 by the polymerase chain reaction technique. The tumors were classified as keratinizing squamous cell carcinoma (KSC), as warty carcinoma (WC), and as basaloid carcinoma (BC). DNA of HPV types 16 and 33 was found in 2/51 KSC, in 12/17 WC, and in 10/10 BC. HPV types 6, 11, and 18 were not detected. Patients with WC and BC were younger, and 78% had VIN III lesions adjacent to the carcinoma. Patients with KSC were older and had a high incidence of dystrophic lesions, including lichen sclerosus, adjacent to the tumor. None of the KSC showed adjacent VIN III. In conclusion, vulvar carcinoma segregates into two categories, of which KSC seems to be the classic type, only rarely associated with HPV infection, and mostly affecting older women; WC and BC constitute an HPV-related subgroup of tumors occurring in younger patients and are associated with VIN III lesions from which they may emerge.