Neonatal oncology: diagnostic and therapeutic dilemmas.

Tumors are a rare but important cause of mortality and morbidity in the neonate. There is a wide spectrum of benign and malignant tumors that can occur, some of which have a unique presentation and behavior in this age group. It is important to recognize that tumors such as stage IVS neuroblastoma, which have a good prognosis in older children, may be rapidly fatal in the newborn and constitute an oncological emergency. Other tumors behave in a less aggressive fashion at this age than in the older child, and should not be overtreated. An increasing number of tumors are being detected by prenatal screening, and understanding of their natural history and management is important. Management of neonatal cancer requires knowledge also of the developmental biology of the neonate, of the way in which they handle drugs, and the increased potential for acute toxicity and long-term morbidity from chemotherapy and radiation therapy.