Patients receive oral fenretinide 3 times a day on days 1-7. Treatment repeats every 3 weeks for up to 8 courses. Patients may receive an additional 22 courses of therapy in the presence of stable or responding residual tumor. Patients with recurrent neuroblastoma, after prior myeloablative therapy with no measurable disease, will stop treatment after 8 courses. Cohorts of 3-6 patients receive escalating doses of fenretinide until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients experience dose limiting toxicity.