- The Duke experience with 56 vulvar Paget disease patients was analyzed emphasizing pathologic features and controversial issues. Nearly all patients were Caucasian, and their mean age was 69 years. The average length of follow-up was 5.6 years. For each case, the following histologic features were evaluated and their association with disease course was examined: pseudo-invasion, adnexal involvement, signet-ring cells, cytologic atypia, glands formation, epidermal acantholysis, parakeratosis, hyperkeratosis, and chronic inflammation. The recurrence rate after surgical management was 32%, with epidermal acantholysis being the only statistically significant risk factor. Stromal invasion occurred in 10 patients (18%), and was not a statistically significant adverse prognostic indicator, although the single patient who died of the disease had the deepest stromal invasion. Recurrence was more common after resections with positive surgical margins, but this correlation was not statistically significant. Intraoperative frozen section analysis of the margins did not reduce recurrence rate, nor was it useful in attaining permanent free margins. The Paget cells were consistently reactive with cytokeratin-7 and carcinoembryonic antigen and unreactive with S-100 protein, HMB-45, and Mart-1. In addition, the tumor cells were usually positive for mucin stains. This profile helps distinguish vulvar Paget disease from its mimics, Pagetoid squamous cell carcinoma and malignant melanoma.