Inclusion Criteria:

          -  Patients with histologically verified ependymoma, with recurrence or progression
             anywhere in the brain and/or spine. Patients are also eligible if they have refractory
             disease, which will be defined as residual tumor which has not been completely cleared
             despite prior treatments. To be eligible, patients' disease must have originated in
             the posterior fossa of the brain

          -  Patient must have either measurable or evaluable tumor as assessed by MRI of the brain
             and total spine

          -  An implanted catheter in the fourth ventricle or posterior fossa tumor cavity attached
             to a ventricular access device or agreement to have one placed.

          -  A minimum of 4 weeks between any prior radiation treatments or bevacizumab infusions
             and first infusion of 5-azacytidine or trastuzumab infusions. A minimum of 2 weeks
             between last dose of any other systemic chemotherapy and first infusion of
             5-azacytidine or Trastuzumab into fourth ventricle

          -  Life expectancy of at least 12 weeks in the opinion of the principal investigator

          -  Lansky score of 50 or greater if ≤16 years of age or Karnofsky score of 50 or greater
             if > 16 years of age

          -  Existing neurological deficits must have been stable for a minimum of 1 week prior to
             study enrollment

          -  Patients must have recovered from the acute toxic effects of all prior anticancer
             chemotherapy

          -  Adequate bone marrow function defined by peripheral absolute neutrophil count (ANC) ≥
             500/µL, platelet count ≥ 50,000/µL (transfusion independent), and hemoglobin ≥ 9.0
             gm/dL (may receive red blood cell (RBC) transfusions)

          -  Patient or patient's legal representative, parent(s), or guardian able to provide
             written informed consent.

          -  Patient with abnormal cardiac function (Shortening fraction less than 28% on
             echocardiogram) will need cardiology clearance prior to enrollment

          -  Normal renal and liver function on basic metabolic panel. Any patients with abnormal
             blood urea nitrogen (BUN), creatinine, alanine aminotransferase(AST) or aspartate
             aminotransferase (ALT) levels will need nephrology and/or gastroenterology clearance
             prior to enrollment

        Exclusion Criteria:

          -  Enrolled in another treatment protocol

          -  Patients with disease that is completely resectable

          -  Has received another investigational or chemotherapy agent within 2 weeks or radiation
             therapy within 4 weeks prior to 5-azacytidine or trastuzumab infusion into the fourth
             ventricle

          -  Patients with any cardiac issues who are not cleared by cardiology for participation
             in the study

          -  Evidence of untreated infection

          -  Pregnant or lactating women