Solitary fibrous tumor of the spinal cord - Report of a case with scrape cytology

BACKGROUND: Solitary fibrous tumor is a rare spindle cell tumor and has bee n forced at a variety of sites. To the best of our knowledge, only two case s of solitary fibrous tumor arising in the spinal cord have been reported; no cytologic findings were documented. CASE: A 62-year-old male presented with a spinal cord tumor. A scrape smear of the resected tumor revealed naked, spindle-shaped nuclei. Some nuclei w ere twisted or had long spindles. In the background, abundant, thin and thi ck collagen fibers were present. Immunohistochemically, the spindle cells w ere positive for CD34 and negative for S-100 protein and alpha-smooth muscl e actin. Histologic diagnosis of the tumor was benign solitary fibrous tumo r. CONCLUSION: Our case indicates that solitary fibrous tumor can occur in the spinal cord and should be differentiated from other benign spindle cell tu mors, such as meningioma and schwannoma. The key cytologic features of soli tary fibrous tumor may be the presence of abundant thin and thick collagen fibers in scrape specimens.