[Medulloblastoma with mandibular metastasis after complete remission of the central nervous system lesions].

A 6-year-old boy presented with headache and vomiting. Brain and spinal MRI demonstrated a large mass in the cerebellar vermis and 4th ventricle and showed thick spinal subarachnoid dissemination. Suboccipital craniotomy was performed and the tumor was totally removed. The histological diagnosis was medulloblastoma. The patient subsequently received craniospinal irradiation, and also received systemic and intrathecal perfusion chemotherapy. Then complete remission was achieved 10 months after operation. Three years later, however, a swelling at the left mandibular angle appeared. A CT scan revealed osteosclerotic lesion. After biopsy was performed, the specimen was detected infiltration of medulloblastoma cells. Bone scintigram showed a single lesion and MRI of brain and spinal cord revealed no recurrence of the central nervous system lesions. He underwent local irradiation and systemic chemotherapy with ICE regimen. This is the rare case of extracranial metastasis following remission of medulloblastoma in childhood.