MRI manifestations of abdominal leiomyosarcoma and literature review / 实用放射学杂志

ABSTRACT

Objective To investigate the MRI characteristics of abdominal leiomyosarcoma and literature review.Methods Preoperative MRI data of 9 cases with leiomyosarcoma proved by pathology were analyzed retrospectively.The size,shape,signal intensity and enhancement type of the lesion were analyzed and some related literatures were reviewed in order to summarize its imaging features.Results In the 9 cases,1 was located in the liver,5 cases in the abdominal retroperitoneul space and other 3 case in the pelvic retroperitoneul space.Before operation,6 cases had wrong diagnosis,including 1 case misdiagnosed as hepatocellular carcinoma with intrahepatic metastases,3 cases as ganglioneuroma and 2 cases as uterine myoma.On plain MRI,5 cases showed iso-/slightly hypo-mixed signal and 4 cases showed hypointensity on T1 WI.Five cases showed iso-/slightly hyper-mixed signal and 4 cases showed iso-/slightly hyper/ hyper-mixed signal on T2WI.On diffusion weighted images (DWI),5 cases showed significant diffusion restriction and 4 cases showed moderate diffusion restriction.On contrast-enhanced MRI,3 cases showed obvious peripheral inhomogeneous enhancement,the enhancement degree in portal vein phase was more obvious than that in arterial phase and was sustained in delayed phase.The lesions showed progressive enhancement and the enhancement was higher in peripheral than central areas.Six cases demonstrated obviously inhomogeneous enhancement in arterial phase,no obvious washout was observed in portal vein phase and delayed phase,and non-enhanced area was still observed in late delayed phase.One lesion in the liver had the sign of pseudocapsule.Conclusion Abdominal leiomyosarcoma has certain characteristic MRI manifestations.Leiomyosarcoma should be considered in the differential diagnosis list,when the lesion is large,with cystic degeneration,necrosis,moderate to significant diffusion restriction on DWI and obvious peripheral enhancement.