title: Malignant perivascular epithelioid cell tumor (PEComa) of the femur: a case report and literature review.
abstract: BACKGROUND
  We describe a case of malignant perivascular epithelial cell tumor (PEComa) arising primarily in the distal left femur of a 47-year-old male.
  
  
  METHODS
  The patient presented with pain accompanied by progressive swelling of his left thigh. Computed tomography (CT) scan and magnetic resonance imaging (MRI) revealed an osteolytic lesion. Curettage of the lesion was reported as a clear cell tumor with recommendation for exclusion of a metastatic clear cell carcinoma. However, thorough examinations did not find any primary site elsewhere, apart from the presence of bilateral pulmonary metastases. Evaluation of the submitted H & E slides identified a malignant PEComa which was further confirmed by subsequent immunohistochemical study.
  
  
  CONCLUSIONS
  The occurrence of PEComa as a primary bone lesion is extremely rare. We present here a malignant PEComa of the distal left femur, and summarize the clinicopathological characteristics of this rare entity with literature review.
  The virtual slide (s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5729035221600545 .
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, 270 Dong An Street, Shanghai, 200032, China.|Department of Oncology, Shanghai Medical College, Fudan University, 270 Dong An Street, Shanghai, 200032, China.
authors.forename: I Weng
authors.initials: IW
authors.lastname: Lao
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, 270 Dong An Street, Shanghai, 200032, China.|Department of Oncology, Shanghai Medical College, Fudan University, 270 Dong An Street, Shanghai, 200032, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yu
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, 270 Dong An Street, Shanghai, 200032, China. softtissuetumor@163.com.|Department of Oncology, Shanghai Medical College, Fudan University, 270 Dong An Street, Shanghai, 200032, China. softtissuetumor@163.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D003475:Curettage; D005266:Femoral Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D054973:Perivascular Epithelioid Cell Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D014057:Tomography, X-Ray Computed
chemical_list: D014408:Biomarkers, Tumor