Epithelial alterations in proximity to invasive squamous carcinoma of the vulva.

The histologic changes within epithelium adjacent to invasive carcinomas theoretically may include the specific lesions that precede the development of the invasive neoplasm, or may reflect the response of host epithelium to the carcinoma or to nonspecific inflammatory stimuli related to ulceration and tissue necrosis. We have studied the vulvar epithelium surrounding squamous carcinomas of 60 women undergoing vulvectomy to determine the frequency and type of potential precursor lesions and their relationship to various biologic parameters. Using modified criteria and nomenclature of the International Society for the Study of Vulvar Disease, we identified some degree of nuclear atypia (either atypical hyperplastic dystrophy or carcinoma in situ) in 72% of patients; in only 3% was there a direct transition from normal epithelium to invasive carcinoma. There was no apparent relationship between the presence of atypia and histologic grade, depth of invasion, size or stage of tumor, or frequency of nodal metastasis. Although direct evidence is lacking, these atypical lesions may serve to identify a population at increased risk for subsequent development of invasive carcinoma.