title: Primary endobronchial synovial sarcoma confirmed by SYT-SSX1 fusion gene transcript by reverse transcriptase polymerase chain reaction.
abstract: Primary sarcomas of lung are rare compared to metastatic sarcomas. Herein, we report a rare case of primary pulmonary synovial sarcoma with polypoid endobronchial growth in a 35-year-old lady who presented with cough and dyspnea. A malignant pulmonary tumor was suspected and left pneumonectomy was performed. Grossly, a non-encapsulated polypoidal endobronchial tumor measuring 6 cm in greatest diameter, with a solid, tan-white cut surface was identified. Microscopically, tumor was characterized by a proliferation of oval to spindle-shaped cells arranged in sheets and fascicles. Focal hemangiopericytomatous pattern was noted. Immunohistochemically, tumor cells were positive for vimentin, BCL-2, MIC-2 and calponin and focally positive for pancytokeratin and epithelial membrane antigen. A subsequent molecular analysis performed using reverse transcriptase-polymerase chain reaction with RNA extracted from paraffin-embedded tissue, revealed SYT/SSX1 fusion gene which confirmed the diagnosis of synovial sarcoma. The utility of immunohistochemistry and molecular techniques in diagnosis of such a rare case is stressed and the relevant literature is discussed.
authors.affiliation: Department of Pathology, Tata Memorial Hospital, Parel, Mumbai, India.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Kumar
authors.forename: Santosh
authors.initials: S
authors.lastname: Menon
authors.forename: Sangeeta B
authors.initials: SB
authors.lastname: Desai
authors.forename: C S
authors.initials: CS
authors.lastname: Pramesh
authors.forename: Hari
authors.initials: H
authors.lastname: Menon
authors.forename: Nirmala Ajit
authors.initials: NA
authors.lastname: Jambhekar
mesh_terms: D000328:Adult; D001984:Bronchial Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D013902:Radiography, Thoracic; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D013584:Sarcoma, Synovial / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery
chemical_list: D015514:Oncogene Proteins, Fusion; C116512:SYT-SSX fusion protein