Primary retroperitoneal perivascular epithelioid cell tumor coexisting with renal angiomyolipoma and tuberous sclerosis: a case report and literature review WU Wen-ming, QIU Hui-zhong, WU Bin, et al.Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China Corresponding author: QIU Hui-zhong, E-mail: qiuhzpumc@yahoo.com.cn Abstract　Objective　The first domestic report of primary retroperitoneal perivascular epithelioid cell tumor ( PEComa). and discuss the clinical pathologic features of the disease. Methods A 29 year-old female patient was admitted in April 2009 in the general surgery department of Peking Union Medical College Hospital and was diagnosed as primary retroperitoneal perivascular epithelioid cell tumor located in the pelvic cavity coexisting with renal angiomyolipoma and tuberous sclerosis. The clinical, imaging, pathology features and treatment of the patient was analyzed retrospectively and related literatures were reviewed. Results The patient had not special symptoms and signs. The imaging methods can easily find the tumor but hard to differentiate it . The final diagnosis depends on the pathologic features and immunohistochemistry techniques. Among present literatures, scarce cases of retroperitoneal PEComa were reported. Conclusions Primary retroperitoneal PEComa is a very rare tumor that arises from mesenchymal tissues. The diagnosis of PEComa mainly depends on the pathological features. Because of the uncertain biologic behavior retroperitoneal PEComa should be followed up for a long term.