儿童胚胎性横纹肌肉瘤的CT和MRI影像学表现分析

Analysis of CT and MRI Imaging Manifestations of Embryonal Rhabdomyosarcoma in Children

目的分析儿童胚胎性横纹肌肉瘤(eRMS)的CT和MRI表现,探讨不同部位eRMS的影像学特点。方法回顾性分析经手术病理或穿刺活检证实的32例eRMS患者的临床影像资料,其中19例行CT平扫及增强扫描,22例行MRI平扫及增强扫描。观察肿瘤部位、CT及MRI特点、骨质改变、有无转移等,并比较躯干、头颈及泌尿生殖道eRMS的影像学表现差异。结果32例患儿中16例位于躯干,8例位于头颈部,7例位于泌尿生殖道,1例位于四肢。肿瘤多表现为边界清晰、较大的单发病灶,躯干eRMS肿块最大径明显大于头颈及泌尿生殖道eRMS肿块的最大径(P<0.001)。CT平扫肿瘤呈不均匀稍低或等肌肉密度;MRI平扫肿瘤表现为T_(1)WI不均匀等或稍低信号、T 2WI不均匀稍高或高信号的囊实性肿块,DWI多呈不均匀高信号;CT或MRI增强扫描肿瘤呈不均匀明显强化,其中葡萄状强化共6例,3例发生于头颈部;形成层现象共8例,多位于躯干。肿块常发生囊变坏死(25/32),围血管现象多见(15/32),可伴有瘤内出血(9/32),以上征象在躯干部最为常见;骨质破坏发生率约32.3%(10/32),于头颈部最多见。eRMS囊变坏死、出血、围血管现象及骨质破坏发生率在躯干、头颈及泌+尿生殖道三组间差异均有统计学意义(均P<0.05)。肿块内钙化罕见(3/32),淋巴转移率、远处转移率分别约28.1%(9/32)、18.8%(6/32),以上征象于各部位间差异无统计学意义(均P>0.05)。结论儿童不同部位eRMS的CT和MRI表现具有共性特征,亦存在一定差异性,结合CT和MRI检查有助于提高疾病诊断准确率。

Objective To analyze the CT and MRI manifestations of embryonal rhabdomyosarcoma(eRMS)in children and explore the imaging characteristics of eRMS in different areas.Methods A retrospective analysis was conducted on the clinical and imaging data of 32 patients with eRMS confirmed by surgical pathology or needle biopsy.Among them,19 cases underwent CT scan with and without contrast,and 22 cases underwent MRI scan with and without contrast.Observe the location,CT and MRI characteristics,bone changes,and presence or absence of metastasis of the tumor,and compare the imaging differences of eRMS in the trunk,head and neck,and urinary and reproductive tract.Results In 32 cases,16 were located in the tract,8 were located in the head and neck,7 were located in the urinary and reproductive tract,and 1 case was located in the limb.Tumors often present as single lesions with clear boundaries and larger size.The maximum diameter of eRMS in the trunk is significantly larger than that of eRMS in the head and neck and urinary and reproductive tract(P<0.001).CT scan without contrast shows unevenly slightly lower or equal muscle density in tumors;On MRI without contrast,the tumor appears as a cystic and solid mass with unevenly equal or slightly low signal intensity on T_(1)WI and unevenly slightly high or high signal intensity on T 2WI,while on DWI,it often presents as uneven and high signal intensity;CT or MRI with contrast showed uneven and significant enhancement of the tumors,with a total of 6 cases showing grape like enhancement,and 3 cases of these occurring in the head and neck;There are a total of 8 cases of formative layer phenomenon,mostly located in the trunk.Tumors often undergo cyst degeneration or necrosis(25/32),perivascular phenomenon is common(15/32),and may be accompanied by intratumoral bleeding(9/32).These signs are most common in the trunk;The incidence of bone destruction is about 32.3%(10/32),most commonly seen in the head and neck.The incidence of cyst degeneration or necrosis,bleeding,perivascular phenomenon,and bone destruction showed statistical differences among eRMS of the trunk,head and neck,and urogenital tract groups(all P<0.05).Calcification within the mass is rare(3/32),with lymph node metastasis rate and distant metastasis rate of about 28.1%(9/32)and 18.8%(6/32),respectively.There is no statistically significant difference in the above signs among different areas(all P>0.05).Conclusion The CT and MRI manifestations of eRMS in different parts of children have common characteristics and also have certain differences.Combining CT and MRI examinations can help improve the accuracy of disease diagnosis.