Tuberculous spondylodiscitis following intravesical Bacille Calmette–Guérin therapy: A case report and systematic literature review

Background: Intravesical Bacille Calmette–Guérin (BCG) therapy is the standard treatment for non-muscle-invasive bladder cancer. Disseminated BCG infection occurs in fewer than 5% of patients, with skeletal involvement (i.e., tuberculous spondylitis) being reported in only 36 cases worldwide. Here, a 77-year-old male with a history of BCG therapy for non-muscle-invasive bladder cancer developed L1/L2 osteomyelitis treated with percutaneous endoscopic transforaminal discectomy, debridement, and anti-tuberculous therapy. Twelve months later, however, the patient required, posterior instrumentation from T10-L5 and anterior column reconstruction at L1–2. Case Description: A 77-year-old male with a history of intravesical BCG therapy for non-muscle-invasive bladder cancer presented with a 2-month history of severe low back pain, focal lumbar tenderness, but no neurological deficits. He was afebrile and the C-reactive protein was elevated (3.0 mg/dL). The lumbar Magnetic resonance imaging (MR) demonstrated L1/2 spondylodiscitis with bilateral psoas muscle nodular lesions suspicious for abscesses. The computed tomography confirmed destructive changes at the L1 inferior endplate and a fracture line through the left L2 pedicle. The patient underwent a percutaneous endoscopic transforaminal discectomy with debridement. The tuberculosis Polymerase chain reaction (PCR) returning positive while TB interferon-gamma release assay (T-SPOT) remained indeterminate. Anti-tuberculous therapy (isoniazid, rifampicin, and ethambutol; pyrazinamide excluded due to Mycobacterium bovis natural resistance) was initiated for 9 months; the patient initially, clinically improved. However, progressive vertebral collapse with kyphotic deformity (11°– 37°) and bilateral posterior thigh pain developed during treatment. Twelve months later, the patient required, posterior instrumentation from T10-L5 with anterior column reconstruction at L1–2, plus the reinstitution of 6 months of additional anti-tuberculous therapy. Conclusion: This represents the 37 th case of BCG-associated tuberculous spondylitis worldwide. High clinical suspicion is required in patients with BCG therapy history presenting with spinal symptoms. Early recognition and appropriate treatment are crucial, though surgical intervention may be necessary for progressive deformity.