Reactive and neoplastic epithelial alterations of the vulva. A classification of the vulvar dystrophies from the dermatopathologist's viewpoint.

The clinical classification of the vulvar dystrophies has traditionally been difficult because most of these lesions present as a white hyperkeratotic patch. An international committee for the study of the vulva designed a histologic classification that consists of: I, hyperplastic type, with or without atypia; II, lichen sclerosus; and, III, mixed dystrophy, with or without atypia. A new classification and a fourth type are proposed by us to sort out a group of strictly benign dermatoses with distinctive histopathologic features which can present clinically as a white patch in the vulva; these are best designated as benign dermatoses. In addition to these, squamous cell carcinoma in situ and Paget's disease may also be manifested as a white patch. Hence, a classification of vulvar diseases with new nomenclature is presented from the dermatopathologist's perspective, based on histologic and clinical features.