Solitary fibrous tumor of filum terminale
A 50-year-old woman suffered from intermittent pain in the lumbosacral area for about 10 years. Her back pain became aggravated progressively and radiated to the bilateral lower extremities 1 year before she arrived at our hospital. A general physical examination was normal. Neurological examination, which included mental status, cranial nerves, cerebellar testing, and motor and sensory tests of the extremities, was also negative. Routine blood tests were within normal limits.\nMagnetic resonance imaging was performed with a commercially available 3.0 Tesla MR scanner (Signa EXCITE HD, GE Healthcare, Milwaukee, WI, USA) and demonstrated a well-defined mass measuring 18×20 mm in transverse diameter located at the level of L2. The irregular intraspinal mass showed isointensity on T1-weighted images and hypointensity on T2-weighted images, and was avidly and homogeneously enhanced after intravenous injection of Gd-DTPA (Magnevist; Bayer Schering Pharma AG, Berlin, Germany) at a dose of 0.1 mmol/kg (Fig. ).\nA L2-L3 laminectomy was performed and an obvious tumor surrounded by nerve bundles was found. The dura mater was opened, as was the overlying arachnoid. Also, the nerve roots of the cauda equina were retracted. A well-defined tumor arising from the filum terminale was exposed. There was a dilated feeding artery and a draining vein running to and from the tumor. The tumor was completely removed. The microscopic appearance showed that the tumor was composed of cytologically scattered spindle cells arranged randomly. Immunohistochemically, the tumor cells had strong and diffuse positivity for vimentin, but were negative for S-100 and EMA antigen. With these findings, SFT of the filum terminale was considered to be the final diagnosis based on the World Health Organization's classification of soft tissue tumors (2002).\nPostoperatively, the patient became free of pain in the lumbosacral area, however, she had numbness of the buttocks and sacral region.