Transtentorial herniation caused by an intracranial mass lesion following high-dose methotrexate

A patient with intracranial osteosarcoma that arose 16 years after radiation therapy for hereditary retinoblastoma developed fatal cerebral edema and brainstem herniation after she received a single dose of intravenous methotrexate. Autopsy demonstrated extensive necrosis of the tumor mass, as well as necrotizing vascular damage within the neoplasm. Although high-dose methotrexate has been shown to be useful in the treatment of primary osteogenic sarcoma, the tumoricidal effects of therapy appear to have caused a fatal rise in intracranial pressure.