Analysis of CT and MRI findings and features of isolated fibroma

LI Hongmei; YU Yonghui

Abstract：Objective To analyze and summarize the CT and MRI findings of solitary fibroma(SFT)and tocompare with pa-thology.Methods 14 cases of isolated fibroma confirmed by pathology and immunohistochemistry were analyzed retrospec-tively.All cases underwent CT examination,of which 5 cases underwent MRI examination and 12 cases underwent enhanced scanning.Results 1)As for the mass location,4 cases located in pelvic cavity,1 case in inguen,1 case in retroperitoneum,2 casesin the intracranial,4 cases in chest,1 case in mediastinum,and 1 case in pancreas;2)For the mass size,the maximum di-ameter was 2.7～15.5cm;3)As for the mass density and signal,of those 14 cases,3 cases showed uniform density and signal,but 11 cases showed uneven appearance.Patchy fat was seen in 1tumor.11 cases showed isodensity and 3 showed slightly low density on CT scan.MRI showed equal and slightly lower signal intensity on T1WI,equal and slightly higher signal intensity on T2WIand uneven tumor signal was presented as mixed signal on T1WI and T2WI;4)As for mass morphology and margins,the tu-mors showed round,quasi-round and elliptic in 9 cases,irregular in 3 cases,lobulated in 2 cases,smooth edges in 10 cases,and uneven edges in 4 cases;5)For the enhancement of tumor,the mass showed obvious enhancement in 7 cases,moderate enhance-ment in 3 cases,marginal annular enhancementin 2 cases.1 case showed uniform enhancement,11cases showed uneven enhance-ment or geographic enhancement.Enhancement of small vessels in or around the tumor was seen in 8 cases and multiple cystic de-generation in the tumor was seen in 5 cases;and 6)With respect to immunohistochemistry,the positive rates of CD34,STAT6,CD99,Bcl-2 and Vimentin were higher in all cases.Conclusion Isolated fibromas are mostly large round or quasi-round masses with uneven density.Small blood vessels in and around the tumor are seen commonly,and cystic lesions can be seen in the tumor.Tumor often appears asmore obvious uneven enhancement.The degree of enhancement may be related to the growth pattern of cells,collagen fibers and blood vessels in the tumor.The density,signal and enhancement characteristics of tumor are correlated with pathological components and the combination analysis can improve the level of the diagnosis of the disease.