Imaging Manifestations of Benign and Malignant Solitary Fibrous Tumors / 中国医学影像学杂志

ABSTRACT

Purpose To analyze the imaging manifestations of solitary fibrous tumors (SFT) so as to improve its diagnosis. Materials and Methods The CT and MRI findings of 24 patients with SFT confirmed pathologically were analyzed retrospectively and compared respectively with their pathological results in terms of lesion's location, size, shape, density (signal), type of enhancement and relationship with the surrounding tissues. Seven patients underwent MRI scan, 5 were with enhanced scan; 17 patients were carried out plain CT scan and 11 were with enhanced CT scan. Results The lesions in the 23 cases were solid and 1 was solid and cystic. Through the imaging diagnosis, 20 cases were diagnosed as benign tumors, 2 cases were diagnosed as malignancies, and 2 benign tumors were misdiagnosed, which showed that the diagnose accordance rate was 91.7%(22/24). On plain CT scans, 5 lesions (maximum diameter5 cm) showed heterogeneous density, 4 of which had calcification and 7 had necrosis; the shapes were round-like or lobulated. On enhanced CT scans, 5 cases presented progressive enhancement pattern, 5 cases showed fast-in and slow-out pattern, 1 case showed slight enhancement pattern. On MRI scan, 4 cases of the solid part of tumors showed isointensity signals on T1WI and isointensity or slight hyperintensity signals on T2WI, 3 cases showed isointensity or low signals on T1WI and low, isointensity or slight hyperintensity signals on T2WI, and slight hyperintensity signal on DWI, the solid part of tumors were strongly enhanced. Two malignant tumors presented features like heterogeneous density, unclear boundary, invasive growth and progressive enhancement pattern. The pathological findings demonstrated that the tumor tissues mainly consisted of spindle cells with rich fibers and vessels. Conclusion The imaging findings of benign and malignant SFT have certain features, malignant SFT have invasive growth signs. The obvious progressive enhancement of solid component which shows isointensity and hyperintensity on T1WI or T2WI may be helpful in the diagnosis of SFT; however, the final diagnosis should be confirmed with histopathology.