Background: The gold standard for diagnosis of central nervous system (CNS) leukemia is presence of blasts in the cerebrospinal fluid (CSF) and/or paralysis of cranial nerves.Case Report: We report the case of 14-year-old male who presented with pallor, petechiae, thorax pain, fundal edema, nodules in the skin and cytopenia. Bone marrow examination revealed 20% of blasts and t(8;21). Cytology of the spinal fluid was normal but MRI showed granulocytic sarcoma and diffuse intraparenchymal and meningeal infiltration. He was diagnosed with acute myeloid leukemia (AML) FAB-M2 with translocation t(8;21) with multiple extramedullary localizations. Rapid resolution of neurological symptoms, disappearance of infiltrates on MRIand hematological remission were achieved following systemic and intrathecal chemotherapy. Initial CNS involvement lead to the subsequent CNS relapse and fatal outcome.Conclusions: CNS localization of leukemia is a major diagnostic and therapeutic problem. Imaging studies should be combined with cerebrospinal fluid examination for a more accurate diagnosis of such disease manifestation.

Keywords: t(8;21), CNS leukemia, AML, MRI