Stage IVS neuroblastoma: a clinical, histological, and biological analysis of 45 cases.

This study reports clinicopathologic and biological analysis of 45 stage IVS neuroblastomas (IVS-NBs). All IVS-NB cases had small or undetectable primary tumors associated with disease involving the liver, skin, or bone marrow. Their ages at diagnosis ranged from 1 day to 12 months, with a median age of 4 months. The primary sites were adrenal in 34 cases, retroperitoneum in two, mediastinum in one, and unknown in eight; the liver was involved in 24 of 31 cases, the bone marrow in 11 of 27, and the skin in 4 of 29. According to the histopathological evaluation (Shimada classification), 43 IVS-NB tumors had a favorable histology, and 2 cases showed an unfavorable histology. Three patients died of progressive disease and six of indirect tumor death. Among these three deceased cases with tumor progression, two cases showed unfavorable histology, and one case had amplified N-myc (20 copies). These data suggest that most IVS-NB can be described as a tumor presenting characteristic dissemination pattern in the younger age group, having a favorable histology and showing an excellent outcome of the patients. However, poor prognosis group in stage IVS does exist, and this group could be detected histopathologically and biologically.