Radiation-induced adult medulloblastoma: a two-case report and review of the literature.

Radiation-induced medulloblastoma is an exceedingly rare phenomenon for which treatment standards have not been established. The literature suggests that these tumors are high grade with aggressive behavior. We report two cases of radiation-induced medulloblastoma which have been treated with full dose re-irradiation with curative intent. In both cases, treatment toxicity and tumor progression proved to be insurmountable obstacles. Further reports are necessary in order to fully characterize this clinical entity so that more effective therapies may be sought.