[A case of relapsed acute myeloid leukemia with brain white matter lesions].

Lesions of the central nervous system (CNS) in acute myeloid leukemia (AML) have a wide range of causes. Apart from infection, virus, fungus and bacteria have to be excluded. Other causes including involvement of leukemia, toxic encephalopathies induced by chemotherapy and radiation therapy, and vascular lesions must be diagnosed differentially for advanced treatment or follow-up. While ultimate diagnosis rests on the collection of cerebrospinal fluid, it is not enough for essential diagnosis. Imaging techniques such as head MRI are powerful tools for diagnosis of intracranial organic lesions, especially in this setting involving leukemia, progressive multifocal leukoencephalopathy (PML) by JC virus infection and treatment-related disseminated necrotizing leukoencephalopathy. A 50-year-old man with AML, who relapsed three times,progressed to an acute consciousness disturbance and was complicated with multiple CNS lesions. He presented with a vesicle formation on his skin, which was pathologically diagnosed as virus infection 1 week after CNS lesions appeared. He was considered to have systemic herpes infection. In this case, considered judgment with multiple approaches would be needed for diagnosis in some cases of AML with the CNS infiltration shadow.