High grade vulvar intraepithelial neoplasia. A clinical, pathologic and molecular virologic study

The clinical, pathologic and molecular virologic features of 42 high grade (grade II-III) vulvar intraepithelial neoplasia (VIN) were analyzed. Data showed that bowenoid VIN was the most frequent type (93%) with a median age of 39, while basaloid VIN had a median age of 77. In bowenoid VIN, asynchronous and/or synchronous intraepithelial neoplasia or invasive squamous cell carcinoma of the lower genital tract was found in 41% of the cases and papillomavirus (HPV) infection in 59%. Hence, all patients with bowenoid VIN showed one or the other condition. None of which was present in any of the 3 patients with basaloid VIN. Most bowenoid VIN were bilateral or multifocal, contrary to basaloid VIN. Southern blot or in situ hybridization detected HPV DNA in 89% of bowenoid VIN. HPV 16 DNA was the most frequently detected type. Vulvoscopy diagnosed subclinical (macular), clinical (papillomatous) and clinical plus subclinical HPV infection in 72% of bowenoid VIN, whereas white or red lesions were diagnosed in basaloid VIN. Seven (23%) of bowenoid VIN patients developed unfavorable events (persistence, recurrence, new occurrence, and progression), and in five of these, HPV 16 DNA was detected. None of the three basaloid VIN patients had unfavorable events.