Multifocal perivascular epithelioid cell tumor of the uterus: report of one case and literature review

Background: The tumor with perivascular epithelioid cells (PEComa) is a rare mesenchymal tumor originating from a perivascular epithelioid cell line. The uterus is the most common location of PEComa, but multifocal lesions are rare. This study aimed to analyze the clinicopathologic and histochemical characteristics of uterine PEComa. Methods: 1 case of uterine PEComa was detected by H&E staining and immunohistochemical SP method. Results: The 41-year-old female patient was admitted to the hospital due to gynecologic ultrasonography which showed a substantial heterogeneous mass in the pelvic cavity. According to the microscopic features and immunohistochemical markers, the tumor was diagnosed as multifocal tumors with perivascular epithelioid cells, specifically located on the serous surface of the uterus and below the right appendix. The immunophenotype of the patient was positive for Vimentin, HMB45, TFE-3 and WT-1, but negative for SMA, S-100, CD10, CK, EMA, CD117, CD31 and Melan-A. Conclusion: PEComa is a rare mesenchymal tumor with benign manifestations. Pathological diagnosis should be combined with morphology and immunophenotype. The characteristic immunomarkers are HMB45, Melan-A and SMA. The understanding of clinical manifestations and pathologic features can improve the diagnosis and prevention of this type of tumor in female patients.