Vulvar Acanthosis with Altered Differentiation (Atypical Verruciform Hyperplasia)

D efinition —Vulvar acanthosis with altered differentiation (VAAD) is defined as vulvar acanthosis with variable verruciform architecture that lacks the nuclear atypia characteristic of vulvar intraepithelial neoplasia (VIN) but exhibits abnormalities in keratinocyte differentiation. It is classed as a risk factor for squamous carcinoma. For the purposes of this discussion, we will address this entity and potential mimics.