Progressive vacuolar myelopathy and leukoencephalopathy in childhood acute lymphoblastic leukemia and transient improvement with vitamin B12

Vacuolar myelopathy (VM) in leukemia is rare. We report a boy with leukemia who developed isolated central nervous system (CNS) relapse during reinduction therapy. 5 months after cranial radiotherapy, he gradually developed quadriparesis. Magnetic resonance imaging revealed an intramedullary lesion which extended through the cervical spine. Serum vitamin B12, folic acid, cerebrospinal fluid methyl malonic acid were normal. Viral screening by ELISA was negative. He had lymphopenia, and reduced immunoglobulins, from a cardiac arrest. Biopsy revealed VM. He responded to weekly vitamin B12 treatment but on the 6th week of the therapy he died after developing periventricular, gliotic, hyperintense lesions in the brain. Pediatr Blood Cancer 2007;49:754–758. © 2006 Wiley‐Liss, Inc.