title: Primary mediastinal clear cell sarcoma: a case report and review of the literature.
abstract: BACKGROUND
  Clear cell sarcoma (CCS) is a rare malignant soft-tissue neoplasm that displays melanocytic markers and exhibits striking histopathological features. The tumour has a predilection for the lower extremities and rarely presents in the mediastinum.
  
  
  METHODS
  We present a case of primary mediastinal CCS in a 57-year-old man. Computer tomography (CT) revealed a 12 × 12 × 7.5 cm mass in the anterior mediastinum. Microscopically, the tumour mainly consisted of epithelioid cells with oval vesicular nuclei and eosinophilic cytoplasm. Immunohistochemically, the tumour was positive for human melanoma black 45 (HMB-45) and vimentin but negative for S-100 and Melan-A. Fluorescence in situ hybridisation (FISH) showed a translocation involving the EWSR1 gene region.
  
  
  CONCLUSIONS
  This report will illustrate that the mediastinum is a potential site for primary CCS and FISH plays an important role in making a conclusive diagnosis.
authors.affiliation: Department of Pathology, Provincial Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, 350001, Fujian Province, People's Republic of China.
authors.forename: Long
authors.initials: L
authors.lastname: Jin
authors.affiliation: Department of Pharmacy, Provincial Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, 350001, Fujian Province, People's Republic of China.
authors.forename: Yuxia
authors.initials: Y
authors.lastname: Sui
authors.affiliation: The State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, People's Republic of China.
authors.forename: Haili
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Pathology, Provincial Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, 350001, Fujian Province, People's Republic of China.
authors.forename: Zhizhong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Pathology, The Eighth Affiliated Hospital, Sun Yat-sen University, 3025 Shennan Middle Road, Shenzhen, 518033, Guangdong Province, People's Republic of China. SGL3016@163.com.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Liu
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008479:Mediastinal Neoplasms / Q000473:pathology*; D008875:Middle Aged; D018227:Sarcoma, Clear Cell / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: Clear cell sarcoma; EWSR1; Fluorescence in situ hybridisation; Mediastinum