Mycobacterium bovis Bacillus Calmette-Guérin (BCG)-Related Sternal Osteomyelitis.

Although the Bacillus Calmette-Guérin (BCG) vaccine causes some complications such as lymphadenitis, cellulitis, and localized musculoskeletal diseases after administration, post-vaccine osteomyelitis is one of the rare complications in healthy children. Diagnosis is often delayed due to atypical presentation. An 11-month-old boy with a normal immune system, who was previously known to be completely healthy and had been vaccinated with BCG, was referred to our center due to a newly noticed firm swelling on the anterior chest wall. There was no evidence of previous tuberculosis infection or contact with a tuberculosis patient. In thorax computed tomography (CT) and magnetic resonance imaging (MRI), there was an irregular soft tissue appearance with heterogeneous contrast, causing lytic changes in the sternum. Histopathological examination of the fine needle aspiration biopsy performed for diagnostic purposes was found to be compatible with post-vaccination BCG-related granulomatous osteomyelitis. Mycobacterium bovis was isolated in the culture sent from the biopsy material. The patient was started on isoniazid, rifampicin, ethambutol, and ciprofloxacin treatments. No complications developed during the treatment, and in the follow-up imaging one month later, a significant shrinkage of the lesion (90%) was detected compared to the previous examination.