Two cases of pediatric neuroblastoma with tumor thrombus in the inferior vena cava

The authors describe two children with abdominal neuroblastoma with radiographic evidence of tumor extension into the inferior vena cava. Imaging studies were suggestive of Wilms tumor, but histologic analysis revealed neuroblastoma. In one patient a pulmonary embolus developed after initiation of cytotoxic therapy; the second patient was prophylactically anticoagulated and had no embolic event.