*2.3.1 New terminology: previous terminology*

VIΝ I: mild dysplasia VIΝ II: moderate dysplasia VIN III: Toy Bowen's disease, severe dysplasia Squamous cell carcinoma in situ, erythroplasia of Queyrat

The lesion is characterized as VIN I when the cellular abnormalities, in comparison with absence of layout, are limited to the lower one-third of the vulvar squamous epithelium, VIN II when the abnormalities extend to the middle third of the epithelium, VIN III when they extend to the upper third of the epithelium, and CIS when lesions occupy all the epithelial layers. Approximately 40% of women present without accompanied symptoms and in the rest cases a background of inflammatory skin disease in the majority being lichen sclerosus exist.

The disease is not characterized as invasive carcinoma as long as the basal lamina remains intact [72–75].
