Mycobacterial Osteomyelitis of the Spine Following Intravesical BCG Therapy for Bladder Cancer.

Osteomyelitis is an infection of the bone that can involve the vertebral column. A rare cause of vertebral osteomyelitis is Mycobacterium bovis after intravesical Bacillus Calmette-Guerin (BCG) therapy for transitional cell carcinoma of the bladder. In this report, we describe the case of a 64-year-old male presenting with constitutional symptoms, progressive thoracic kyphosis, and intractable T11 and T12 radiculopathies over the proceeding six months. A CT scan revealed erosive, lytic changes of the T12 and L1 vertebrae with compression of the T12 vertebra. An MRI demonstrated T11-12 osteomyelitis with intervening discitis and extensive paraspinal enhancement with a corresponding hyperintensity on a short tau inversion recovery (STIR) sequence. A needle aspiration grew out Mycobacterial tuberculosis complex that was pansensitive to all antimicrobial agent therapies, except pyrazinamide on culture, a finding consistent with an M. bovis infection. The patient's infection and neurologic compromise resolved after transthoracic T11-12 vertebrectomies with decompression of the spinal cord and nerve roots as well as T10-L1 instrumented fusion and protracted antimicrobial therapy. The epidemiology and natural history of M. bovis osteomyelitis are reviewed and the authors emphasize a mechanism of vertebral inoculation to explain the predilection of M. bovis osteomyelitis in males after intravesical BCG therapy.