Neuroblastic tumors in young adults as a sequela of malignant neuroblastoma: report of two cases.

Neuroblastoma, ganglioneuroblastoma, and ganglioneuroma share the same histological spectrum which originates from neural crest cells. We present herein two young adult patients with neuroblastic tumors with lymph node metastases. Both the patients were diagnosed incidentally as having retroperitoneal masses, which showed little or no immature cells despite coexistence of lymph node involvement. The tumors were considered to represent spontaneous regression of malignant neuroblastoma. Radiologists should consider the possibility of spontaneous regression of neuroblastic tumors, when poorly enhanced multi-component masses at the retroperitoneum with lymph node involvement are visualized.