Nontuberculous mycobacterial infection of a metastatic brain neoplasm in an immunocompromised patient.
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.
Little
Ann A
AA
Department of Neurology, University of Michigan Medical Center, 1924 Taubman Center, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA. alitt@umich.edu
Gebarski
Stephen S
SS
Blaivas
Mila
M