Biology of pediatric peripheral neuroectodermal tumors.

The pediatric peripheral neuroectodermal tumors which include neuroblastoma, peripheral neuroepithelioma and Ewing's sarcoma may correspond to distinct neural crest cell lineages or tumors arrested at different stages of neural crest development. Besides a brief commentary on the salient clinical features of these tumors, this review examines how cell and molecular biological studies have contributed to a re-classification of these tumors. The differentiation of these tumors is reviewed with a particular emphasis on retinoic acid induced differentiation of neuroblastoma as a model to identify genes important in controlling cell growth, suppression of tumorigenicity and induction of differentiation.