Lenalidomide in Treating Young Patients With Recurrent, Progressive, or Refractory CNS Tumors

Inclusion Criteria: * Patients with a histological diagnosis of a primary CNS tumor (including histologically benign brain tumors (e.g. low-grade glioma) that is recurrent, progressive, or refractory to standard therapy; patients with intrinsic brain stem or diffuse optic pathway tumors do not require histological confirmation of disease but should have clinical and/or radiographic evidence of progression * Karnofsky Performance Scale (KPS for \>= 16 yrs of age) or Lansky Performance Score (LPS for ≤ 16 years of age) ≥ 60 assessed within two weeks prior to registration * Patient must be able to swallow capsules * Patients must have recovered from any significant acute toxicity associated with prior therapy; patients must have no known curative therapy available; patients will be eligible regardless of the number of prior therapies, as long as other eligibility criteria are met * Chemo: Prior use of thalidomide is acceptable; patients must have: * Received their last dose of known myelosuppressive anticancer chemotherapy or biological therapy at least three (3) weeks prior to study registration * Received their last dose of nitrosourea or mitomycin-C at least six (6) weeks prior to study registration * Received their last dose of other investigational agent or an anticancer drug known to not be myelosuppressive at least seven (7) days prior to study registration * XRT: Patients must have had their last fraction of craniospinal irradiation ≥ 3 months prior to registrati…