Several pathologic conditions are associated with the formation of white plaques on the vulva, which are clinically referred to as leukoplakia. Lichen sclerosis is seen histologically as atrophy of the epidermis with underlying dermal fibrosis. This abnormality is seen in postmenopausal women, who develop pruritic white plaques of the vulva. It is not thought to be premalignant. Loss of pigment in the epidermis (vitiligo) can also produce leukoplakia. Inflammatory skin diseases, such as chronic dermal inflammation, squamous hyperplasia (characterized by epithelial hyperplasia and hyperkeratosis), and vulvar intraepithelial neoplasia (characterized by epithelial atypia or dysplasia), can also present with leukoplakia. A term related to leukoplakia is vulvar dystrophy, but this refers specifically to either lichen sclerosis or squamous hyperplasia. Because the latter is sometimes associated with epithelial dysplasia, it is also referred to as hyperplastic dystrophy. It is most commonly seen in postmenopausal women. The male counterpa of lichen sclerosis, called balanitis xerotica obliterans, is found on the penis. Paget's disease is a malignant tumor that can be found in the breast or the vulva. The latter is seen clinically as pruritic, red, crusted, sharply demarcated maplike areas. Histologically, these malignant lesions reveal single anaplastic tumor cells surrounded by clear spaces ("halos") infiltrating the epidermis. These malignant cells stain positively with PAS and mucicarmine stains. Reference: Robbins & Cotran Pathologic Basis of Disease, 9edition