Shukla PS, Xia R, Lin LH, et al. - Owing to the rarity of perivascular epithelioid cell tumors (PEComas), which are mesenchymal tumors that co-express smooth muscle and melanocytic markers, there is limited information concerning natural history that poses challenges in making accurate risk stratification. Proposal of five different prognostic classification systems (2 for PEComa of all sites and 3 specific for gynecologic PEComa) has been made. In this study, 13 new cases of gynecologic PEComa were assessed for clinicopathologic features, and all 5 prognostic algorithms were tested in a total of 67 cases of gynecologic PEComa (54 cases from previously published studies). The predictive accuracy was evaluated by building receiver operating characteristic curves and calculating area under curve (AUC). Along with showing high sensitivity and specificity, the ‘modified gynecologic-specific criteria’ yielded the highest AUC (0.864). In this work, ‘modified gynecologic-specific’ algorithm is identified as valuable for predicting clinical outcome of gynecologic PEComa with high accuracy and is validated for prognostic stratification of gynecologic PEComa.