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Abstract
Introduction/Background Perivascular epithelioid cell tumors (PEComas) is a rare subtype of mesenchymal tumors composed of perivascular epithelioid cells. The main concern after the diagnosis is predicting the disease behavior: four classification systems have been proposed for this purpose based on size, pathological characteristics, and immunohistochemical characteristics.
Methodology We retrospectively reviewed the prospectively collected pathologic registry to identify all cases of uterine PEComa diagnosed and treated at our center. Moreover, we conducted a systematic review of the literature to identify all published cases of uterine PEComa pathologically confirmed. For each identified case with available data, we applied all the proposed classification systems (FOLPE, FOLPE modified, Bennet, and Schoolmester) and assessed their performance with cox regression analysis.
Recurrence-free survival Kaplan meier curves. A: Folpe system; B: Folpe modified system; C: Schoolmester system; D: Bennet system
Cause-specific death Kaplan meier curves. A: Folpe system; B: Folpe modified system; C: Schoolmester system; D: Bennet system
Results We identified seven cases of uterine PEComa diagnosed and treated at our center. The search strategy identified 51 papers for a total of 121 cases of uterine PEComa.The uterine corpus was the most frequent localization (n=55; 45.7%), and uterine bleeding was the clinical presentation in 36 (32.5%) cases. In most cases, the diagnosis was at the final pathological examination (n=39; 83%). Among those who recurred or dead due to disease, the median time to recurrence was 18 (2–82; IQR 4–21.7) months and the median time to death was 17.5 (5–43; IQR 12–35) months. The malignant group reported a higher rate of recurrence and cause-specific death than the benign group in all classifications. The Bennet system (figure 1–2) reported the highest HR for relapse and death due to PEComa in the malignant group versus the benign group (HR 14.17; 95% CI 4.29 – 46.72 for relapse; HR 33.17, 95% CI 4.39 – 4246.79 for death).
Conclusion Preoperative diagnosis of uterine PEComa is uncommon without specific clinical presentation. Among proposed classification systems, the Bennet system reported the highest ability to distinguish between benign and malignant behaviors.