Synovial sarcoma of the thoracic spine.

BACKGROUND CONTEXT Synovial sarcoma is an uncommon malignant neoplasm occurring chiefly in young adults. It often presents as a solid well-circumscribed soft-tissue mass in the extremities of young adults. Despite its proximity to joints, it has been well established that the tumor cells do not display features of synovial differentiation but instead appear to have a primitive epithelial phenotype. There is no report of a lower thoracic paravertebral synovial sarcoma in an adult male. PURPOSE To describe our management in a patient with a synovial sarcoma of the thoracic spine and to review previously published cases. STUDY DESIGN Case report. METHODS A 60-year-old man presented with a 5-month history of right upper quadrant abdominal pain radiating to his back in a band-like fashion; shortness of breath on exertion; and increasing pain when standing, sitting, or walking. Magnetic resonance imaging (MRI) demonstrated a large right-sided paraspinal mass sitting on the eighth and ninth ribs, pressing on the T9 vertebrae and abutting the T7 and T8 vertebral level exhibiting "Triple Intensity." Plain films demonstrated a right-sided paraspinal mass extending from the T7-T8 level to T10. Bone scintigraphy showed increased uptake on the right thoracic spine at T7-T8 to T10. Computed tomography (CT) imaging revealed a right paraspinal mass with lytic changes in the T9 vertebral bodies. A right-sided thoracotomy was performed, and the patient underwent subsequent radiation therapy. Absence of the tumor was shown by an MRI scan after the operation. RESULTS Complete resolution of the patient's complaints was achieved. The diagnosis is supported by plain radiographs, bone scintigraphy, magnetic resonance and CT imaging studies, and histologic and immunohistochemical evidence. CONCLUSIONS Synovial sarcomas are rarely present in the paravertebral region of the thoracic spine. A careful radiographic study of the tumor permitted early preliminary diagnosis, confirmed upon histopathologic analysis. Despite lytic changes, removal of a periosteal layer permitted sparing of the vertebral bodies.