Multifocal leukoencephalopathy in adult leukemia: histologic features and etiologic considerations

A number of structural alteration in brains of leukemic children have been attributed to intrathecal administration of methotrexate and radiation therapy. We report an instance of asymptomatic encephalopathy in an adult who received thio-TEPA (by subarachnoid injection) as treatment for leukemic meningitis. The lesions were microscopic, confined to cerebral white matter and included: vacuolation, myelin destruction, axonal swelling, gliosis, deposition of mineral salts and aggregates of large foamy cells. The etiology of this condition remains undetermined.