Mathew Denny, de Lima Heliodora, Mahomed Nasreen
Department of Radiology, University of the Witwatersrand, South Africa.
Helen Joseph Hospital, Johannesburg, South Africa.
SA J Radiol. 2019 Jan 10;23(1):1662. doi: 10.4102/sajr.v23i1.1662. eCollection 2019.
Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in the paediatric age group, ranking fourth in frequency after central nervous system tumours, neuroblastomas and nephroblastomas. Embryonal RMS of the biliary tree is considered a rare entity, with the most common clinical presentation being that of obstructive jaundice. We present the case of a 4-year-old boy who presented with hepatomegaly and obstructive jaundice. Biochemically, there was evidence of elevated ductal enzymes with conjugated hyperbilirubinaemia. The magnetic resonance imaging (MRI) features were consistent with a biliary RMS with the differential diagnosis of a choledochal cyst initially included based on the computed tomography images. The diagnosis of embryonal biliary RMS was later confirmed on histology. This case illustrates the importance of considering malignant aetiologies in paediatric cases of obstructive jaundice, as this entity is infrequently described in the literature and may mimic the appearance of a choledochal cyst. The demonstration of enhancement of intraductal material within the biliary tree on MRI and the presence of arterial waveforms within the intraductal mass on ultrasound assists in the differentiation between biliary RMS and a choledochal cyst.
横纹肌肉瘤（RMS）是儿童年龄组中最常见的软组织肉瘤，发病率在中枢神经系统肿瘤、神经母细胞瘤和肾母细胞瘤之后排第四。胆管树胚胎型RMS被认为是一种罕见的实体，最常见的临床表现是梗阻性黄疸。我们报告一例4岁男孩，表现为肝肿大和梗阻性黄疸。生化检查显示有导管酶升高及结合胆红素血症的证据。磁共振成像（MRI）特征与胆管RMS一致，基于计算机断层扫描图像最初的鉴别诊断包括胆总管囊肿。胚胎型胆管RMS的诊断后来经组织学证实。该病例说明了在儿童梗阻性黄疸病例中考虑恶性病因的重要性，因为该实体在文献中很少被描述，且可能类似胆总管囊肿的表现。MRI上胆管树内导管内物质的强化表现以及超声检查中导管内肿块内动脉波形的存在有助于鉴别胆管RMS和胆总管囊肿。
