Primary pulmonary synovial sarcoma presenting with a large lump mass in the left upper mediastinum: A case report.

Primary pulmonary synovial sarcoma is a rare lesion that occurs in 0.5% cases of lung malignancies. Chest computed tomography (CT) reveals a heterogeneously enhancing mass in the lobe or hilum of the lungs, frequently calcified and with pleural invasion. Involvement of the mediastinum in the course of primary pulmonary synovial sarcoma, in particular detection of a large mass in the mediastinum as the sole initial imaging manifestation, is extremely rare, which may contribute to a delayed diagnosis or misdiagnosis. The present case report describes an extremely rare case of a patient with primary pulmonary synovial sarcoma presenting with a large mass in the left upper mediastinum. A 59-year-old patient was admitted to the Department of Respiratory Medicine of Taizhou People's Hospital in May 2014, complaining of a persistent cough and blood sputum for 2 weeks. Following admission, a chest CT showed a large mass in the left upper mediastinum. Thoracoscopy was performed and revealed that the left pulmonary artery was engulfed by the mass, and thus surgical resection of the tumor was abandoned. The patient was definitively diagnosed with primary pulmonary synovial sarcoma following the histopathological and immunohistochemical analysis of biopsy specimens obtained via thoracoscopy. Following the final diagnosis, the patient was transferred to the Department of Oncology for chemotherapy treatments with ifosfamide and doxorubicin. Unfortunately, no partial regression was achieved after two rounds of chemotherapy, and the patient was lost to follow-up 3 months after the diagnosis was confirmed. The present case may promote the consideration of primary pulmonary synovial sarcoma in the differential diagnosis of patients who present with a large mass in the mediastinum.