Solitary Fibrous Tumors of the Central Nervous System: Clinical Features and Imaging Findings in 22 Patients

Introduction: Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm originating in the central nervous system (CNS), with imaging features currently not well known. The purposes were to describe and characterize clinical features and imaging findings of CNS SFT. Methods: We retrospectively reviewed computed tomographic (CT; n = 10) and magnetic resonance (MR) images (n = 18) of 22 patients with SFT (13 males and 9 females; mean, 47.6 years) with associated clinical records. Results: Each lesion was found as a solitary, well-defined mass, ranging in size from 12 to 70 mm (mean, 38 mm). The tumor shape was roundlike in 16 cases (72.7%) and irregular in 6 cases (27.2%). The cerebellopontine angle zone was the most affected area (n = 6). On precontrast CT scans, 10 cases showed predominantly hyperattenuation (n = 9) and isoattenuation (n = 1). No lesion contained calcification, and 2 cases showed bone invasions. All 18 tumors examined by MR imaging showed homogeneous hypointensive (n = 5) or isointensive (n = 7) signal intensity and heterogeneous mixed isointense and hypointense signal intensity (n = 6) on T1-weighted images, whereas most tumors were predominantly isointense (n = 13) and hypointense (n = 4) to the cortex on T2-weighted images; on postcontrast CT and MR images, enhancement was marked homogeneous (n = 10) or heterogeneous (n = 12). Fourteen tumors had thickening of the meninges adjacent to the tumor. Conclusions: Although SFT is a rare neoplasm in the CNS, it should be considered in the differential diagnosis. The most affected area is the cerebellopontine angle zone. Solitary fibrous tumor tends to have some imaging features, such as high attenuation on CT, isointense to hypointense signal intensity on MR images, and marked enhancement.