A case of adult onset medulloblastoma during maintenance chemotherapy for anaplastic astrocytoma one year after radiotherapy.

Multiple primitive intracranial tumors with different histological characteristics are uncommon. Although coexistence of a medulloblastoma with glial tumors has been reported in children, medulloblastoma is rarely found in adults, especially those older than 40 years of age. We present an extremely rare case of a medulloblastoma developing in a 40-year-old male undergoing maintenance chemotherapy for anaplastic astrocytoma for 21 months after radiotherapy. Initially, he complained of intractable epilepsy characterized by complex partial seizures. Magnetic resonance imaging (MRI) revealed a slightly enhanced mass lesion in the left insula region. He underwent subtotal removal of the tumor and it was histologically diagnosed as anaplastic astrocytoma. After 19 months of treatment with temozolomide (TMZ) and radiotherapy, he presented with vertigo and headache. A homogeneously enhanced mass had developed in the left cerebellar hemisphere. He received gross total resection of the second tumor, pathologically diagnosed as medulloblastoma. In conclusion, this is the first case report of an adult medulloblastoma coexisting with anaplastic astrocytoma.