White sponge nevus.

A case is presented of white sponge nevus involving the vaginal, labial, and oral mucosae of a 34-year-old woman. White sponge nevus is a rare, benign, autosomal dominant leukokeratosis that predominantly affects the oral mucosa. Less frequently, it affects extraoral sites including the vulvovaginal mucosa. In this case, histopathologic study of vulvovaginal lesions, subsequent examination of extragenital mucosae, and inquiry into the family history led to the correct diagnosis. The genetics, clinical appearance, and histopathology of white sponge nevus are discussed in relation to the differential diagnosis of oral and vaginal leukokeratoses.