Abstract:
Malignant rhabdoid tumors (MRTs) are rare but lethal solid neoplasms that overwhelmingly affect infants and young children. While the central nervous system is the most common site of occurrence, tumors can develop at other sites, including the kidneys and soft tissues throughout the body. The anatomic site of involvement dictates tumor nomenclature and nosology. While the clinical and imaging manifestations of MRTs and other more common entities may overlap, there are some site-specific distinctive imaging characteristics. Irrespective of the site of occurrence, somatic and germline mutations in SMARCB1, and rarely in SMARCA4, underlie the entire spectrum of rhabdoid tumors. MRTs have a simple and remarkably stable genome but can demonstrate considerable molecular and biologic heterogeneity. Related neoplasms encompass an expanding category of phenotypically dissimilar (nonrhabdoid tumors driven by SMARC-related alterations) entities. US, CT, MRI, and fluorodeoxyglucose PET/CT or PET/MRI facilitate diagnosis, initial staging, and follow-up, thus informing therapeutic decision making. Multifocal synchronous or metachronous rhabdoid tumors occur predominantly in the context of underlying rhabdoid tumor predisposition syndromes (RTPSs). These autosomal dominant disorders are driven in most cases by pathogenic variants in SMARCB1 (RTPS type 1) and rarely by pathogenic variants in SMARCA4 (RTPS type 2). Genetic testing and counseling are imperative in RTPS. Guidelines for imaging surveillance in cases of RTPS are based on age at diagnosis. ©RSNA, 2024 Supplemental material is available for this article.
摘要:
恶性横纹肌样瘤(MRT)是罕见但致命的实体瘤,绝大多数影响婴幼儿。虽然中枢神经系统是最常见的发生部位,肿瘤可以在其他部位发展,包括肾脏和全身的软组织.受累的解剖部位决定了肿瘤的命名和疾病学。虽然MRT和其他更常见实体的临床和影像学表现可能重叠,有一些特定部位的独特影像学特征。无论发生地点如何,SMARCB1中的体细胞和种系突变,在SMARCA4中很少见,是横纹肌样肿瘤的整个谱的基础。MRT具有简单且非常稳定的基因组,但可以表现出相当大的分子和生物异质性。相关肿瘤包括表型不同(由SMARC相关改变驱动的非横纹肌样瘤)实体的扩展类别。US,CT,MRI,和氟脱氧葡萄糖PET/CT或PET/MRI有助于诊断,初始分期,和后续行动,从而为治疗决策提供信息。多灶性同步或异时横纹肌样肿瘤主要发生在潜在的横纹肌样肿瘤易感性综合征(RTPS)的背景下。在大多数情况下,这些常染色体显性疾病是由SMARCB1(RTPS1型)的致病性变体驱动的,很少是由SMARCA4(RTPS2型)的致病性变体驱动的。基因检测和咨询在RTPS中是必不可少的。RTPS病例的影像学监测指南基于诊断时的年龄。©RSNA,2024补充材料可用于本文。