软组织原发性低度恶性肌纤维母细胞肉瘤的CT与MRI表现

CT and MRI Findings of Primary Low-Grade Malignant Myofibroblastic Sarcomas of Soft Tissue

目的探讨原发于软组织的低度恶性肌纤维母细胞肉瘤(LGMS)的CT与MRI特点,以提高其影像诊断水平。方法回顾性分析9例经病理证实的软组织原发性LGMS的CT与MRI表现,单独行CT与MRI检查各4例,1例同时行CT和MRI检查。结果 9例软组织LGMS中,在CT上2例边界较清晰,2例可见大量不规则钙化影,4例行增强扫描,动脉期2例明显不均匀强化,2例呈轻中度强化,且以边缘强化为主,仅有1例行静脉期扫描,肿瘤强化程度进一步增高,1例出现双肺转移;在MRI上肿瘤呈长T1、长T2信号,增强扫描3例呈明显均匀强化,2例瘤体边缘强化显著,瘤内坏死液化区未见强化。结论软组织原发性LGMS的CT与MRI表现缺乏特征性,确诊依靠病理检查。

Objective To discuss CT and MRI features of primary low-grade malignant myofibroblastic sarcomas of soft tissue in order to improve its diagnostic level.Methods A total of 9 patients with pathologically-confirmed primary lowgrade malignant myofibroblastic sarcoma of soft tissue were enrolled in this study.Simple CT scanning was performed in 4cases,simple MRI was employed in 4 cases,and both CT and MRI were carried out in one case.The imaging manifestations were retrospectively analyzed.Results Among the 9 cases with primary low-grade malignant myofibroblastic sarcoma of soft tissue,the lesion had a clear border on CT scan in 2,showed a large number of irregular calcification in 2.Contrastenhanced CT scanning was employed in 4 cases,and in arterial phase obvious heterogeneous enhancement was demonstrated in 2 cases,moderate enhancement at the tumor periphery was seen in 2 cases.Venous phase scanning was performed in only one patient,which showed that the enhancement degree of the tumor became further increased.Bilateral pulmonary metastasis was detected in one case.On MRI the lesion was characterized by long T1 and long T2 signals.In 3 cases the lesions displayed obvious enhancement on contrast-enhanced scanning and in 2 cases significant peripheral enhancement was observed.The liquefaction or necrosis area within the tumor showed no enhancement.Conclusion Primary low-grade malignant myofibroblastic sarcomas of soft tissue are lack of characteristics CT and MRI signs,the confirmation of the diagnosis depends on the pathology examination.