A massive retroperitoneal neuroblastoma with stenosis of the inferior vena cava in a 5-month-old boy.

Neuroblastoma is the second most common retroperitoneal tumour in children after Wilms' tumour. When it originates in the retroperitoneum, neuroblastoma usually presents as an abdominal mass with clinical manifestations of nausea, vomiting and weight loss. Imaging studies of this tumour demonstrate a heterogeneous mass with an irregular capsule and visible calcifications. Encasement and compression of the abdominal vessels, especially the inferior vena cava, are often observed. However, stenosis of the inferior vena cava has never been reported to be associated with this tumour. Here, we present a case of a 5-month-old boy with a right retroperitoneal tumour with extensive encasement of the inferior vena cava and significant narrowing of its distal part between the venous bifurcation and the tumour capsule. To our knowledge, this is the first case of neuroblastoma with this manifestation in a child.