Pott's Disease Caused by Mycobacterium bovis Following Intravesical BCG Therapy for Bladder Cancer

Bacillus Calmette-Guerin (BCG) are attenuated strains of Mycobacterium bovis, which is part of the Mycobacterium tuberculosis complex. BCG is used for bladder cancer therapy. 80 year old man presented with severe back pain, paraplegia, urine retention. Past history included rheumatoid arthritis, bladder cancer. He was diagnosed with recurrent bladder cancer (T1, high grade lamina propria superficial invasion) in June 2016 (previously diagnosed 14 years ago, treated with BCG). Patient had transurethral resection of tumor in August 2016, after which he got 6 weekly cycles of intravesical BCG. He underwent cystoscopies with no evidence of residual disease. No history of concurrent illness during therapy. He was initially admitted 1 month ago with back pain: MRI showed thoracic (T6-T7) epidural abscess, vertebral osteomyelitis/diskitis; he underwent T6-T7 hemilaminectomies, drainage of abscess, cord decompression. Operative cultures were initially negative. He was discharged with empiric broad spectrum antibiotics. Repeat MRI during this admission showed extensive inflammation at T6-T7: diskitis, osteomyelitis, epidural abscess, more non enhancing material in the disc space, progressive edema in pedicles and lamina, worse cord compression. Neurosurgery evaluated patient: deemed to be poor surgical candidate given his extensive comorbidities, advanced age. His operative AFB cultures turned positive 4 weeks after surgery (MTB complex by DNA probe). Therapy started with Isoniazid, Rifampin, Ethambutol, Pyridoxine, Dexamethasone. The isolate was sent to state lab: whole genome sequencing showed M. bovis BCG strain. Susceptibility testing is pending. BCG therapy of superficial bladder cancer is a recommended treatment modality. Early infectious complications occur within 3 months, late infections after 1 year. In >2000 patients treated with BCG, infectious complications occurred in <5%. Potts disease following BCG therapy is rare but has been described; the time of onset can be from 14 days to 12 years after therapy. In patients treated with BCG for bladder cancer, clinicians must have a high index of suspicion for infectious complications, as early initiation of therapy yields better outcomes. All authors: No reported disclosures.