Patients < 12 months of age with stg 3, 4, or 4S disease who achieve a very good PR (VGPR) to chemo (with the exception of resolution of skin or liver metastases in stage 4S patients) proceed to observation. Patients 12-18 months of age with stg 3 or 4 who achieve VGPR proceed to isotretinoin therapy. No VGPR proceed to retrieval chemo - cyclophosphamide and topotecan hydrochloride. Some patients may also undergo surgery.