Primary Synovial Sarcoma of the Mediastinum: A Case Report and Review of the Literature

Background: Synovial sarcomas most commonly occur in the soft tissues of the extremities of young adults. A primary occurrence in the mediastinum is very rare with only a few reported cases in the world literature. Study aims: to insist on the rarity of this pathology, its imaging features and the importance for recognizing unusual presentation of this aggressive neoplasm to aid appropriate clinical management. Cases: Here in, we report a rare case of primary monophasic spindle cell synovial sarcoma of the mediastinum in a 31-year-old man who had an incidental finding of such a tumor. The imaging studies on admission showed 12 cm anterior- middle mediastinal mass with multiple metastases in the lung, pleura, mediastinal lymph nodes and spine. An ultrasound-guided percutaneous needle biopsy of a cervical extension of the mass permitted histopathology and immuno histochemical analysis which supported the diagnosis of monophasic spindle cell synovial sarcoma. The patient was treated by chemo-therapy without response. Conclusion: A wide range of neoplasms both primary and metastatic occurs in the mediastinum which poses considerable diagnostic difficulties. A synovial sarcoma should be considered in the differential diagnosis. Imaging can guide percutaneous needle biopsy of the tumor and evaluate its stage. Immunohistochemistry can be very helpful for an accurate diagnosis