儿童胸壁横纹肌肉瘤的CT诊断

CT Diagnosis of Chest Wall Rhabdomyosarcoma in Children

目的原发于胸壁的横纹肌肉瘤(RMS)少见,关于儿童胸壁RMS影像学表现的研究较少,本文分析了儿童胸壁RMS的CT影像学表现,以提高儿童胸壁RMS的诊断准确率。资料与方法回顾性分析经手术病理证实为胸壁RMS的5例患儿的CT影像资料,总结患儿RMS的CT影像特点。结果 5例患儿中,病灶位于前胸壁1例,后胸壁2例,侧胸壁(腋下)2例。病灶形态呈类圆形或梭形,部分肿块呈浅分叶。平扫病灶密度不均匀、可见斑片状低密度坏死区2例,密度较均匀3例;5例病灶均未见钙化及脂肪组织。肿块侵犯邻近椎管1例;肿块突入胸腔压迫肺组织1例,压迫心脏及肝脏1例;肿块包绕血管生长2例。5例病灶均紧邻肋骨、肱骨、肩胛骨及脊柱骨等,有骨质破坏1例。增强扫描5例病灶呈不均匀轻-中强化,以周边强化明显,病灶内可见较多增粗、扭曲的供血动脉影,其内坏死区不强化。2例出现肺转移灶,1例出现胸腔积液及腹腔积液,1例出现淋巴结转移。结论儿童胸壁RMS的CT表现为胸壁较大或巨大软组织肿物,密度均匀或欠均匀,内无钙化及脂肪组织,部分有坏死区,邻近组织受推压甚至侵犯,可出现淋巴结及远处转移;增强扫描后病灶呈不均匀轻-中度强化,以周边强化明显。结合临床表现,综合分析增强CT影像表现可提高诊断准确率。

Purpose Primary chest wall rhabdomyosarcoma（RMS） is very rare with limited imaging characteristic studies in the literature. This paper analyzes the CT imaging features of chest wall RMS in children to improve the diagnostic accuracy. Materials and Methods The imaging data of contrast enhanced CT scan of pathology confirmed chest wall RMS in five children were analyzed. Results The lesion was located in the anterior chest wall in one case, in the posterior chest wall in two cases, and the lateral chest wall in two cases（axillary）. The tumors were round or spindle in shape with shallow spiculation. Plain CT showed heterogeneous density with patchy low-density necrotic area in two cases, and homogeneous attenuation in three patients. In all five cases there was no calcification or fatty tissue. The tumor involvement of adjacent spinal canal was seen in one case. Visceral compression was evident including lung parenchyma in one case, heart and liver in one case. Tumor blood vessel growth was seen in two cases. All five lesions were adjacent to the ribs, humerus, scapula and the spine with bone destruction in one case. On contrast enhanced scan, all five cases demonstrated heterogeneous mild to moderate enhancement, more prominent in the periphery. There were enlarged feeding arteries. Necrotic areas did not enhance. In two cases there were pulmonary metastases. Pleural effusion and ascites were identified in one case. There was lymph node metastasis in one case. Conclusion The CT manifestation of children’s chest wall RMS for chest wall include large soft tissue mass, heterogeneous density, no calcification or fatty tissue, partial necrosis, adjacent tissue compression, lymph node or distant metastasis. Combining with clinical manifestations, comprehensive analysis of contrast enhanced CT imaging can improve diagnostic accuracy.