CT and MRI manifestations of extrapleural solitary fibrous tumors:Ten cases report and literature review

Objective To investigate CT and MRI characteristics of extrapleural solitary fibrous tumors(ESFT).Methods Imaging findings of 10patients with ESFT proved pathologically were retrospectively analyzed,among them 4underwent CT and 6underwent MR scan.Results The lesions located in the abdomen(n=3),pelvic cavity(n=2),region of foramen magnum(n=2),left orbit(n=1),root of right neck(n=1)or left temporal subcutaneous region(n=1).Seven lesions present as solitary round or oval,while 3present as irregular masses.Borders of 8lesions were clear,while of others were partly unclear.Diameters of the lesions ranged from 2.3cm to 20.6cm,with a mean of(7.78±6.82)cm.Plain CT showed solid combined with cystic component in 1case and solid in 3cases with isodensity,of which necrosis were seen in 2and multiple calcification were seen in 1case.The solid part of ESFT progressively enhanced in 3cases and early mild enhancement in 1case.On MRI,1case manifested as hypointensity on T1WI and T2WI,1as isointensity on T1WI and hypointensity on T2WI,3as isointensity on T1WI and hyperintensity on T2WI,and 1as hyperintensity on both T1WI and T2WI.There were 3cases showing string or patchy hypointensity on T2WI.Obvious enhancement of ESFT on postcontrast MR scans was observed in all 6cases receiving MR scan.Conclusion ESFT has some specific imaging features.MR T2WI showing mainly hyperintensity tumor with string or patchy hypointensity is of high value for diagnosis of ESFT.