MRI findings of primary myxofibmsarcoma in the extremity soft-tissues / 实用放射学杂志

ABSTRACT

Objective To investigate the MRI characteristics of primary myxofibrosarcoma (MFS) in the extremity soft-tissues.Methods The MRI of 14 cases of MFS confirmed by operation and pathology were analyzed retrospectively.Results In the 14 cases,9 were in the thigh,3 in the lower leg,and 2 in the upper arm.The volumes of the tumors were relatively big and all located in the subcutaneous fat or superficial inter-muscular space.The tumor showed expanding growth and had well-defined boundary.On T1 WI,one case showed isosignal intensity,one showed equal signal intensity mostly,and 12 cases showed patch slightly low signal intensity;On fat suppression T2 WI and STIR,tumors showed high-low mixed signal intensity,which mainly showed high signal intensity;On MRI enhanced study,inhomogeneous enhancement was observed in most of the tumors,and "tail sign" was showed in 11 cases.Conclusion MFS is of characteristics on MRI,the position of tumor is shallow,the tumor is relatively big and has clear boundary.On T1 WI,most tumors show iso-low mixed signal intensity.On fat suppression T2WI and STIR,tumors show high-low mixed signal intensity;On enhanced MRI,inhomogeneous enhancement and "tail sign" are its characteristic signs.