MRI findings of inflammatory myofibroblastic tumor of the soft tissue / 中华放射学杂志

ABSTRACT

Objective To describe MR findings in inflammatory myofibroblastic tumor(IMT)of the soft tissue.Methods MR manifestations of 11 cases of IMT of the soft tissue were retrospectively analyzed,and the MR findings were correlated with surgical and histological results.Results The pathological classification of the tumors was type Ⅰ in 1 case,type Ⅱ in 4 cases.mainly type Ⅱ admixed with type Ⅰ in 3 cases,and mainly type Ⅱ admixed with type Ⅲ in 3 cases.In 4 cases with primary tumor,the tumors were spheroid in shape,with well-defined margin and pseudocapsule.In 2 cases with primary axillary tumor and 5 cases with recurrent tumor,the tumors were irregular in shape,with ill-defined margin and invasion of adjacent structures.The tumors were mainly isointensive in T1-weighted images.Tumors of different pathological classifications had different signal intensities in T2-weighted images1 case of type Ⅰ tumor was bright4 cases of type Ⅱ tumor and 3 cases of type Ⅱ tumor admixed with type Ⅰ tumor were slig}ltly bright;3 cases of type Ⅱ tumor admixed with type Ⅲ were isointense or slightly hypointense in signal.All of the 11 eases in the study exhibited"pitaya cross-section sign"in T2-weighted sequence,which referred to discrete punctuate foci of relatively hypointensity in the background of hyperintensity,slightly hypointensity or isointensity.All of the 11 cases exhibited inhomogeneously significant enhancement after gadolinium administration.In the follow-up of the 6 cases of primary tumor,4 cases had recurrence,1 case had no recurrence,and 1 ease was lost in the follow-up process.In the follow-up of the 5 cases of recurrent tumor,4 cases showed recurrence again,and 3 cases were lost in the follow-up process.Conclusions The IMT of the soft tissue has characteristic MR features.The signal intensity of the tumor on T2-weighted sequence could reflect the pathological type of the tumor to some extent."pitaya cross-section sign"could be a pathogenomic sign of the IMT of the soft tissue.