5例儿童纵隔恶性横纹肌样瘤临床及影像学特征

Clinical and imaging characteristics of mediastinal malignant rhabdoid tumor in five patients

目的探讨儿童纵隔恶性横纹肌样瘤(MRT)的临床与影像学特征,提高对该病的认知。方法收集2013年1月-2016年1月就诊于首都医科大学附属北京儿童医院的5例纵隔MRT患儿病历资料,术前均行CT平扫,其中3例行增强扫描,1例行MRI平扫检查,总结分析其临床及影像学特点。结果 5例患儿中,男1例、女4例;中位发病年龄5岁4个月(5个月～8岁4个月);肿瘤位于上纵隔3例、前纵隔1例、后纵隔1例;呈类圆形或不规则形;肿物边界均欠清晰,与周围软组织分界不清;瘤体多较大,最大径范围(3.1～8.9)cm;CT扫描2例可见囊变,囊性部分与实性部分边界模糊,呈渐进性变化;2例有钙化;3例伴有大量胸腔积液;CT增强扫描可见,肿瘤实性部分不均匀持续性强化。1例MRI平扫,肿瘤表现为混杂信号肿块,以T1WI稍低信号,T2WI稍高信号为主。5例中4例为局限性肿瘤,另外1例伴有远处转移。本组5例纵隔MRT患儿,4例死亡,仅1例经过手术、化疗及放疗的综合性治疗已存活37个月。结论纵隔MRT是一种高度侵袭性恶性肿瘤,极易复发及进展,影像学主要表现为纵隔内较大不均质肿块,可伴有囊变、钙化及胸腔积液。

Objective To summarize the clinical and imaging features of malignant rhabdoid tumor（MRT） of mediastinum in children. Methods A retrospective analysis was conducted in five patients with mediastinal MRT from January 2013 to January 2016 in our hospital. CT scan was performed in all of the five patients and three cases underwent CT contrast enhanced. The MRI scan was performed in only one patient. Results five cases included four females and one male, aged from five months to eight years four months old, with the median age of five years four months old. tumors located in the upper mediastinum（three cases）, the anterior mediastinum（one case） and the posterior mediastinum（one case）. The shape of the tumor was circular or irregular. Most tumors were large with the maximum diameter ranged from3. 1 cm to 8.9 cm. CT manifestations included solid-cystic lesions with ill-defined margin and heterogeneous density. Three cases demonstrated large pleural effusion and two cases revealed calcification. The tumors of two cases showed heterogeneous continuous enhancement. On MRI（one case）, the tumors demonstrated a heterogeneous mass with the main signal of low signal on T1 WI and high signal on T2 WI. Metastatic lesion was discovered preoperatively in one case. Among the five cases with mediastinal MRT, four patients died of disease and only one case survived for 37 months after the surgery, chemotherapy and radiotherapy.Conclusions Mediastinal MRT was a highly aggressive malignant tumor which progressed rapidly. The principal imaging findings included a large heterogeneous mass with cystic degeneration, calcification and pleural effusion.