OUTLINE: All patients undergo resection of the primary tumor and N-myc determination within 6 months of age, unless critically ill, then are treated according to risk. Patients with amplified N-myc or with indeterminate N-myc amplification but with other risk features are treated per protocol GER-NB90. Stage 4S patients who are critically ill or thrombocytopenic receive doxorubicin, vincristine, and cyclophosphamide over 7 days. Patients with no amplification of N-myc are observed for 6 months (until between 12 and 18 months of age). Patients with minimal residual disease (less than 10% or diameter no greater than 2-5 mm) continue observation, while those with residual disease but no disease progression undergo repeat biopsy. Patients whose biopsy indicates tumor regression also continue observation. All other patients, including those with disease progression, are treated per protocol GER-NB90.