儿童颞骨横纹肌肉瘤的CT和MRI表现

CT and MRI findings of temporal bone rhabdomyosarcoma in children

目的探讨颞骨横纹肌肉瘤(RMS)的CT、MRI表现特征。方法选取经手术病理证实的7例RMS的CT和MRI资料,对其起源部位、大小、边界、形态、信号特点、表观弥散系数(ADC)值和强化特征及免疫组织化学和Ki67表达程度特征进行回顾性分析。结果7例患者中,起源于颞骨岩尖3例,岩骨体2例,中耳乳突区2例。肿瘤大小为1.9 cm×2.1 cm×2.9 cm~8.1 cm×4.7 cm×3.9 cm,均呈不规则、边界清楚肿块,T1WI低信号、T2WI高信号,增强后呈均匀性强化5例、非均匀性强化2例,肿瘤ADC值范围为(0.89~1.04)×10^(-3) mm^(2)/s,平均(0.92±0.07)×10^(-3) mm^(2)/s。肿瘤Ki67表达程度范围为50%~80%。结论颞骨横纹肌肉瘤MRI表现为颞骨的溶骨性、边界清楚的软组织肿块,T1WI低信号、T2WI高信号,增强后呈明显强化,肿瘤细胞Ki67均呈高表达为其典型特征。

Objective To investigate CT and MRI imaging features of rhabdomyosarcomas(RMS)of the temporal bone.Methods CT,MR and immunohistochemical(IHC)data of 7 patients with RMS confirmed by surgical pathology were col‐lected.The tumor location,size,boundary,shape,signal characteristics,apparent diffusion coefficient(ADC)value,enhance‐ment characteristics and IHCindicators and Ki67 expression were retrospectively analyzed.Results Of those 7 patients,3 cases originated from petrous apex of temporal bone,2 cases from petrous body,and 2 cases from mastoid region of middle ear.The tumor size ranged from 1.9 cm×2.1 cm×2.9 cm-8.1 cm×4.7 cm×3.9 cm,with well-defined and irregular margins,low signal on T1WI,high signal on T2WI and homogeneous enhancement in 5 cases and heterogeneous enhancement in 2 cases.The ADC value of tumor ranged from 0.89 to 1.04(mean 0.92±0.07)×10^(-3) mm^(2)/s.Ki67 proliferative index was high in all tumors ranging from 50%to 80%.Conclusion RMS of temporal bone is osteolytic soft tissue mass,with clear margins,hypointensity on T1WI and hyperintensity on T2WIand DW imaging with strikingly enhancement and Ki67 highly expression.