Clinical and Radiographic Features for Differentiating Solitary Fibrous Tumor/Hemangiopericytoma From Meningioma

Objective: Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) and meningioma exhibit similar radiographic features; however, they differ in their prognoses. Preoperative differentiation between them is important for determining the treatment and follow-up plan. The aim of this study was to determine the factors that can be used to differentiate SFT/HPC from meningioma and World Health Organization (WHO) grade I from grade II meningioma. Methods: The analysis included 84 cases: 5 of SFT/HPC, 72 of WHO grade I meningioma, and 7 of WHO grade II meningioma. Clinical characteristics and conventional magnetic resonance imaging, perfusion magnetic resonance imaging, and magnetic resonance spectroscopy (MRS) LCModel parameters were evaluated via multivariate logistic regression analysis to identify the factors that distinguish SFT/HPC from meningioma. Results: Patients with SFT/HPC were mostly men and were younger than those with meningioma. The percentage of T2-weighted images in meningioma was greater than that in SFT/HPC. There were significant differences between SFT/HPC and meningioma in levels of glutamate, phosphocholine, myo-inositol, or glycerophosphocholine + phosphocholine derived from long echo-time MRS, and myo-inositol derived from short echo-time MRS. Stepwise logistic regression analysis revealed that the age of <45 years and myo-inositol in short echo-time MRS of ≧6.347 were associated with a diagnosis of SFT/HPC with high sensitivity and specificity. However, no factors were found that differentiated WHO grade I meningioma from WHO grade II meningioma. Conclusions: Age and myo-inositol level calculated from MRS are useful factors for distinguishing SFT/HPC from meningioma preoperatively.