Bacillus Calmette-Guérin Osteomyelitis Mimicking Spinal Metastasis from Urothelial Cell Carcinoma of the Bladder

A 66-yr-old male presented with progressively worsening back pain 5 mo after undergoing radical cystectomy and bilateral extended pelvic lymph node dissection for bacillus Calmette-Guérin–refractory pTisN0M0 urothelial carcinoma of the bladder. Imaging revealed lytic lesions in the 10th and 11th vertebral bodies of the thoracic spine that were suspicious for metastasis and cord compression. The patient underwent computed tomography–guided biopsy of the abnormalities, which showed no evidence of malignancy but revealed chronic inflammatory infiltrate with cultures positive for Mycobacterium bovis. The patient was treated with isoniazid, rifampin, ethambutol, and pyrazinamide.