儿童炎性肌纤维母细胞瘤的CT和MRI表现

Imaging features of CT and MRI of inflammatory myofibroblastic tumor in pediatric patients.

目的探讨儿童炎性肌纤维母细胞瘤(IMT)的CT和MRI表现,以期提高临床医生对儿童IMT影像表现的甄别能力。方法回顾性分析上海市儿童医院2015年1月至2020年8月经手术病理确诊的8例儿童IMT患者的CT和MRI影像和临床资料。8例中行CT平扫8例、CT增强扫描7例、MRI平扫和增强扫描2例。结果8例IMT的发生部位包括腹部4例、肺1例、四肢2例和左颈部1例。CT平扫表现为低密度或等密度团块软组织影,边界清晰或欠清,形态不规则,位于腹部的肿块体积较大;增强扫描肿块实性成分表现为均匀或不均匀明显强化,延迟期强化更显著,1例部分病灶周围环形强化明显。MRI表现为T1WI呈低信号、T2WI呈等或高不均匀信号;增强扫描表现为T1WI轻度至明显不均匀强化。病理结果显示IMT主要由梭形细胞和炎症细胞组成,免疫组织化学检测全部病例平滑肌源性抗体(SMA)阳性。结论儿童IMT的CT和MRI影像表现特征对提示IMT的诊断有一定的价值,其确诊仍依赖于病理和免疫组织化学检查。

Objective To investigate CT and MRI features of inflammatory myofibroblastic tumor(IMT) in pediatric patients, in order to improve the discrimination ability of IMT of the clinical doctors. Methods The CT and MRI findings and clinical data of 8 cases with IMT verified by surgical pathology from January 2015 to August 2020 in Shanghai Children′s Hospital were retrospectively analyzed. Of which, 8 cases had CT scan, 7 cases had CT enhancement scan, and 2 cases had MRI scan and enhancement scan. Results The IMT of 8 cases located in abdomen(4 cases), lung(1 case), limbs(2 cases), and neck(1 case). The CT scan imaging of the IMT presented with soft tissue masses of low or equal density with well or ill-defined boundary and irregular shape, and the IMT located in abdomen was larger than in the other locations;the solid components of the IMT presented with homogeneous or inhomogeneous enhancement with obviously delayed enhancement, and circumference enhancement of the lesions was presented in 1 case with CT enhancement scan. The MRI scan imaging of the IMT manifested low signal on T1 WI, uneven equal or high signal on T2 WI;slightly to markedly uneven enhancement was presented with MRI enhancement scan. Tumors were mainly composed of spindle-shaped fibrous cells and inflammatory cells on pathology. On immunohistochemistry study, smooth muscle-derived antibody was positive in all cases. Conclusion To some extent, the CT and MRI features of IMT in pediatric patients are helpful for inferring the diagnosis of IMT, but the final diagnosis of IMT relies on pathology and immunohistochemistry study.