Solitary fibrous tumor presenting as a symptomatic intraspinal mass: Case report

OBJECTIVE AND IMPORTANCE: Mesenchymal, nonmeningeal tumors of the central and peripheral nervous systems are rare. Specifically, the solitary fibrous tumor, which occurs in both benign and malignant forms, was first described in the pleura and more recently in a number of sites, including the mediastinum, abdomen, upper respiratory tract, nasopharynx, and orbit. It has not, however, previously been known to involve the spine or to induce cord compression. CLINICAL PRESENTATION: We describe the case of a 33-year-old man who presented with back pain, progressive myelopathy, and lower extremity dysesthesias. Imaging studies demonstrated an intradural extramedullary mass at T7-T8. INTERVENTION: At surgery, the lesion was found to be firm, fibrous, intimately apposed to the T8 sensory nerve root but emanating from neither root nor dura. Histologically, the tumor was composed of spindle cells in a storiform pattern with extensive collagen deposition in the intercellular matrix. Immunohistochemistry showed diffuse positive staining of tumor cells for CD34 antigen but negative staining for S100 and EMA, a profile that is consistent with a histopathological diagnosis of solitary fibrous tumor and that effectively rules out meningioma and nerve sheath tumor. CONCLUSION: This is the first report of an intraspinal solitary fibrous tumor, a rare entity that should be included in the differential diagnosis of intradural extramedullary spinal neoplasms.