title: Nontuberculous mycobacterial infection of a metastatic brain neoplasm in an immunocompromised patient.
abstract: BACKGROUND
  Nontuberculous mycobacterial infections occur in immunocompromised patients but so rarely involve the central nervous system (CNS) that they may not be included in a differential diagnosis of CNS lesions in such patients.
  
  
  OBJECTIVE
  To illustrate a putative mechanism for nontuberculous mycobacterial infection of the CNS via breakdown of the blood-brain barrier by metastatic neoplasm.
  
  
  RESULTS
  A 56-year-old man who had undergone renal transplantation in February 2003 and was taking an immunosuppressive regimen of mycophenolate mofetil and cyclosporine was seen in the emergency department after a syncopal episode. Head computed tomography revealed a single focal occipital lesion with vasogenic edema. Hospital admission and further workup led to diagnosis of metastatic carcinoma infected with nontuberculous mycobacteria in the setting of a disseminated nontuberculous mycobacterial infection.
  
  
  CONCLUSIONS
  This case illustrates that breakdown of the blood-brain barrier by metastatic neoplasm may provide a route of access for a pathogen that is not normally seen in the CNS.
authors: Department of Neurology, University of Michigan Medical Center, 1924 Taubman Center, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA. alitt@umich.edu
authors: Ann A
authors: AA
authors: Little
authors: Stephen S
authors: SS
authors: Gebarski
authors: Mila
authors: M
authors: Blaivas