Vulvar intraepithelial neoplasia III: a clinical study of the outcome in 113 cases with relation to the later development of invasive vulvar carcinoma.

OBJECTIVE: To determine the outcome of 113 women with vulvar intraepithelial neoplasia (VIN), particularly in reference to the later development of invasive vulvar carcinoma.
METHODS: All cases of VIN III seen between 1961 and 1993 were reviewed.
RESULTS: Seven of eight untreated cases of VIN III progressed to invasive vulvar cancer within 8 years, and the eighth regressed spontaneously. Four women developed invasive vulvar carcinoma 7-18 years after treatment. Thus, 3.8% of treated patients later developed invasive vulvar carcinoma, and 87.5% of untreated patients progressed to invasive carcinoma.
CONCLUSION: There is a substantial risk that untreated VIN III will progress to invasive cancer.