Enhancement of the white matter following prophylactic therapy of the central nervous system for leukemia: radiation effects and methotrexate leukoencephalopathy.

The authors report a case of fatal necrotizing leukoencephalopathy following prophylactic therapy of the central nervous system for acute lymphoblastic leukemia. The clinical, CT, and neuropathological findings are described. The CT scan demonstrated symmetrical white-matter enhancement. Histological analysis was consistent with the effects of irradiation and methotrexate. The differential diagnosis of the clinical and CT findings is discussed. Brain biopsy is the diagnostic procedure of choice.