title: Clear cell sarcoma of soft tissue in right parapharyngeal region: report of a rare case.
abstract: Clear cell sarcoma (CCS), initially named malignant melanoma of soft parts, is a rare malignant neoplasm typically involving deep soft tissue of the extremities, in close proximity to tendons and aponeuroses. Here we describe a case of clear cell sarcoma of the right parapharyngeal region in a young female aged 20 years. MRI detected a mass about 4.4 cm×3.4 cm×3.0 cm, located in the right parapharyngeal area and between the external pterygoid and the medial pterygoid. Microscopically, most of the tumor cells were epithelioid with palely eocinophilic cytoplasm arranged in sheets. Pleophorism of tumor cells were not marked. Immunohistochemical analysis shows that the tumor cells were positive for vimentin, S-100, HMB45 and MelanA, and negative for AE1/AE3, actin-sm, desmin, CD117, TFE-3, and P63. Ki67 index was about 5%.
authors.affiliation: Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University Shenyang 110001, China ; Institute of Pathology and Pathophysiology, China Medical University Shenyang 110001, China.
authors.forename: Chuifeng
authors.initials: C
authors.lastname: Fan
authors.affiliation: Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University Shenyang 110001, China ; Institute of Pathology and Pathophysiology, China Medical University Shenyang 110001, China.
authors.forename: Juanhan
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University Shenyang 110001, China ; Institute of Pathology and Pathophysiology, China Medical University Shenyang 110001, China.
authors.forename: Lianhe
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University Shenyang 110001, China ; Institute of Pathology and Pathophysiology, China Medical University Shenyang 110001, China.
authors.forename: Xuyong
authors.initials: X
authors.lastname: Lin
authors.affiliation: Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University Shenyang 110001, China ; Institute of Pathology and Pathophysiology, China Medical University Shenyang 110001, China.
authors.forename: Enhua
authors.initials: E
authors.lastname: Wang
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D018227:Sarcoma, Clear Cell / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000473:pathology*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor
keywords: Clear cell sarcoma; alveolar soft part sarcoma; clear cell sarcoma of soft tissue; malignant melanoma; parapharyngeal region