title: Granulocytic sarcoma mimicking HSV encephalitis.
abstract: BACKGROUND
  Granulocytic sarcomas, or chloromas, are extramedullary collections of immature granulocytes. Central nervous system involvement is rare and of those cases described, most are complications of acute myelogenous leukemia.
  
  
  METHODS
  A 40-year-old man with chronic myelogenous leukemia presented with seizure and encephalopathy. Magnetic resonance imaging of the brain revealed temporal T2 hyperintensities with gyriform cortical enhancement. Cerebrospinal fluid showed mild pleocytosis and elevated protein. Electroencephalography demonstrated periodic lateralized epileptiform discharges. Acyclovir was initiated for herpes simplex encephalitis, however, follow-up MRI showed extension of the lesion. MR spectroscopy suggested tumor, confirmed by brain biopsy. Postradiation MRI showed a significant decrease in lesion size.
  
  
  CONCLUSIONS
  Granulocytic sarcoma can present as intraparenchymal cerebral lesions in patients with chronic myelogenous leukemia and may mimic herpes simplex encephalitis.
authors.affiliation: Departments of Neurology, University of Maryland, Baltimore, MD 21201, USA.
authors.forename: Reena S
authors.initials: RS
authors.lastname: Shah
authors.forename: Robert K
authors.initials: RK
authors.lastname: Shin
authors.forename: Rudy J
authors.initials: RJ
authors.lastname: Castellani
mesh_terms: D000212:Acyclovir / Q000627:therapeutic use; D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D001706:Biopsy; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000209:etiology / Q000473:pathology* / Q000532:radiotherapy; D003937:Diagnosis, Differential; D004569:Electroencephalography; D020803:Encephalitis, Herpes Simplex / Q000188:drug therapy / Q000473:pathology*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000150:complications; D008279:Magnetic Resonance Imaging; D008297:Male; D023981:Sarcoma, Myeloid / Q000209:etiology / Q000473:pathology* / Q000532:radiotherapy
chemical_list: D000998:Antiviral Agents; D000212:Acyclovir