Vulvar intraepithelial neoplasia (severe atypia and carcinoma in situ). A clinicopathologic analysis of 41 cases.

Forty-one cases of vulvar intraepithelial neoplasia (VIN) were analyzed clinicopathologically with emphasis on the changes in age-specific incidence rates, coexisting condylomata, coexisting koilocytotic atypia, subsequent invasive carcinoma and response to therapy. The number of cases referred to in the interval from 1975 to 1982 was 26 compared with 15 in the interval from 1966 to 1974. In addition, the percentage of patients in each group younger than 45 years of age was 66% after 1975 versus 33% prior to 1975. The yearly incidence of patients older than 45 years of age remained constant. The association of condyloma or marked koilocytosis in the neoplastic epithelium per se correlated with a younger mean age (31.1 and 31.8 years, respectively) than the absence of condyloma or marked koilocytosis (45.5 years and 47.5 years, respectively). Carcinoma developed in five patients (10.2%), and the mean age of the group was 55 years. Four of the five developed carcinoma within 3 years of diagnosis of the VIN. The incidence of persistence of the VIN lesion or recurrence following local excision was 22% over a mean following of 6.1 years. Spontaneous regressions were not reported in this patient population. Vulvar intraepithelial neoplasia appears to be a disease of multiple etiology which affects at least two populations. The younger patients are associated with papilloma-virus infection, and have a low risk of progression to cancer. The older patients have a variable history of condylomata, and a higher risk of developing invasive cancers of the anogenital region. The most important risk factor from the clinicopathologic standpoint appears to be age.