Mycobacterial brain abscess possibly due to bacille Calmette-Guérin in an immunocompromised child. 
Disseminated infection with bacille Calmette-Guérin (BCG) is rare, even in immunocompromised patients who receive BCG injections as immunotherapy or immunization.  When such infection occurs, it is usually in patients with decreased cellular immunity.  A 6-year-old Caucasian girl who was receiving maintenance chemotherapy for acute lymphoblastic leukemia presented with symptoms of meningitis.  A temporal-lobe biopsy revealed acid-fast bacilli that were identified as Mycobacterium bovis BCG.  Neither the patient nor any family members had been immunized previously.  Appropriate therapy resulted in a complete recovery.