The overall goal of this study is to find out what effects, good and/or bad, a low
dose and a high dose of lenalidomide have on children, adolescents and young
adults with recurrent (has come back after being treated), refractory (has not gone
away with previous treatment), or progressive (is not responding to previous
treatments) Juvenile Pilocytic Astrocytomas (JPA) and Optic Pathway Gliomas
(OPG).

the United States, it is standard treatment for patients with high-risk neuroblastoma (NBL) to receive the drugs carboplatin, etoposide and melphalan (CEM) as the preparative regimen in Consolidation therapy prior to Autologous Stem Cell Transplant (ASCT). BuMel Consolidation therapy has recently been studied in patients with high-risk NBL in some European countries. The findings from those studies indicate that the use of BuMel prior to ASCT may be linked to an increase in the survival rate for patients when compared to CEM. Those studies also indicate that the chance of the disease coming back (a relapse) may be lower among the patients who received BuMel Consolidation therapy. In North America the BuMel combination is considered experimental. In this study, researchers want to find out if a combination of busulfan and melphalan (BuMel) can be given as Consolidation therapy prior to ASCT for subjects with newly diagnosed high-risk NBL. The main goal of this study is to find out what effects, good and/or bad, a BuMel preparative regimen given before ASCT has on people with newly diagnosed high-risk NBL.

Ependymoma is a type of rare childhood cancer that occurs in the brain and spinal cord. Survival statistics are generally disappointing with a 5-year survival of 50-64%. The standard of care for ependymoma is maximal surgical resection followed by radiation therapy directed at the primary site of disease.

Radiation therapy is associated with immediate and long-term toxicities in children, especially young children. For this reason, it has been the practice of some doctors not to give radiation therapy to children with ependymoma when the tumor has been completely surgically removed. The investigators who designed this study have created strict measures to choose those who will not receive additional treatment after surgery and careful follow-up to minimize the risks to those who are assigned to observation only.

To collect information about the patient's leukemia and to seek the optimal treatment for children with ALL based on the individual level of risk of the cancer coming back after treatment. The risk groups are defined as a result of recent research conducted by the Children's Oncology Group (COG). We would like to learn if the use of an experimental intrathecal therapy (ITT), which has been given to many people with ALL and has been well tolerated, would be better at preventing relapse in the central nervous system and improve disease outcomes in children with High Risk ALL.

This study is for patients enrolled on COG protocols.. The main purpose of this study is to develop a mechanism for tracking and retaining patients enrolled on COG
protocols. Participants can expect to be in the study for life or until requested by participant.