Material from 111 invasive primary vulvar carcinomas was reviewed in order to study the histopathologic changes adjacent to the neoplasia. The histopathologic characteristics of the adjacent tissue were divided into categories. Dystrophic lesions were adjacent to invasive cancer in 57.6% of the cases, carcinoma in situ (CIS) in 21.6% and epithelial changes suggestive of human papillomavirus infection in 18.9%. A spectrum of epithelial changes, ranging from hyperplastic dystrophy without atypia to CIS, was found adjacent to nine cases of invasive carcinoma (8.1%). In 40.5% of the vulvar carcinomas there were no specific alterations surrounding the neoplasia. These data show that dystrophies and CIS were adjacent to invasive carcinomas in nearly 60% and 20% of cases, respectively.