Vulvar intraepithelial neoplasia: a synopsis of recent developments

This review highlights recent advances in our understanding of preneoplastic squamous lesions of the vulva, from a pathologist's perspective. Vulvar intraepithelial neoplasia (VIN) is the preferred nomenclature for these lesions. VIN lesions may or may not be symptomatic and have a variable clinical appearance. Three histological types of VIN are recognized. Although the term bowenoid papulosis was introduced for an entity distinct from VIN, current evidence indicates that cases with this clinical pathological presentation are better classified as VIN. The natural history of VIN is unpredictable, although age is regarded as a risk factor for developing invasive disease. The histopathological differential diagnosis of VIN includes several lesions, among which is a newly described entity-multinucleated atypia of the vulva. VIN1 lesions are diagnosed uncommonly. Whereas the incidence of invasive vulvar carcinoma in North America has not changed, VIN lesions are being increasingly detected. Finally, some histological features of VIN are important to consider with respect to therapy.