Primary pulmonary synovial sarcoma: Diagnosis on squash smears

Synovial sarcomas are rare tumors accounting for approximately 5-10% of soft tissue sarcomas. They occur predominantly in the extremities, followed by head and neck. Primary pulmonary sarcomas are very rare and comprise only 0.5% of all primary lung malignancies. The diagnosis is established only after sarcomas like primary lung malignancies, and metastatic sarcomas have been excluded. For synovial sarcomas that arise at unusual locations, a definitive diagnosis is challenging and requires the use of ancillary diagnostic procedures such as immunohistochemistry (IHC) and molecular genetic techniques for confirmation of diagnosis. We report a case of 29-year-old male who had right lower lobe lung mass. He underwent right lower lobectomy. Intraoperative squash smears revealed spindle cell sarcoma. Subsequent histopathology and IHC confirmed the diagnosis as synovial sarcoma. We report this case on account of its rarity and to emphasize the utility of intraoperative squash smears in the diagnosis of such cases, which has been under-utilized in clinical practice.