Mycobacterium bovis BCG spinal osteomyelitis in a patient with bladder cancer without a history of BCG instillation

BCG has been used as intravesical immunotherapy for the treatment of bladder carcinoma. However, this treatment is not harmless and may lead to complications, with a reported incidence of systemic BCG infection ranging from 3% to 7%. We report a case of culture-proven Mycobacterium bovis (BCG) vertebral osteomyelitis in a 72-year-old patient with bladder carcinoma who was treated with intravesical mitomycin C but did not receive BCG. Cultures from biopsy recovered isolate resembling Mycobacterium tuberculosis biochemically, but resistant to pyrazinamide (PZA). The patient was originally started on a four-drug antituberculous regimen of isoniazid, rifampin, ethambutol and PZA. After genotypic analysis identified the organism as M. bovis (BCG), the regimen was changed to isoniazid and rifampin for 12 months. The patient responded well to this treatment. This case is unique as the patient received only intravesical mitomycin and did not receive BCG, implying the possibility of transmission from contaminated equipment.