RESUMEN
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.
RESUMEN
Immunohistochemistry (IHC) is a powerful tool in the surgical pathologists' armamentarium. The requests for IHC and the list of monoclonal antibodies have increased tremendously in the past decade. Issues concerning technical reproducibility, uniformity of interpretation, inter-laboratory comparability, and quality assurance are assuming greater importance due to the increased availability of IHC and its impact on diagnosis and therapy. An attempt has been made to give a current perspective of this simple and yet, in some aspects, a complex tool.