Mechanism of direct spread of abdominal neuroblastoma: CT demonstration and clinical implications.

Neuroblastoma, a malignant tumor of neural crest origin, is the most common extracranial solid tumor in children. In 1971 Evans et al. introduced a clinical staging for neuroblastoma. Over sixty percent of patients present with neuroblastoma beyond stage I. Despite more aggressive therapy there has been only minimal improvement in survival. Since 1978, all patients with neuroblastoma have had CT scanning as part of their initial evaluation at our institution. Children with abdominal neuroblastoma beyond stage I form the basis of this report. Selected cases illustrating the permeative nature of neuroblastoma and the mechanism of direct abdominal spread by CT scanning are presented. The tumor originates in the retroperitoneum and spreads to the abdominal aorta where it gains access to the subperitoneal space via the celiac axis and superior mesenteric artery. These vessels course from the aorta to their ultimate destination within their peritoneal folds. These folds form the interconnecting space (subperitoneal space) between the retroperitoneum and the peritoneal organs. Such scanning is extremely sensitive in detecting neuroblastoma with early infiltration into adjacent tissues and contiguous spread through abdominal spaces. The clinical implications of the permeative nature of neuroblastoma and the mechanism of contiguous abdominal spread are discussed.