Coinfection of Streptococcus agalactiae and Tuberculous Osteomyelitis of Tibia Mimicking Brodie's Abscess in an Immunocompetent Adult: A Case Report

Introduction: Coinfection of tuberculous osteomyelitis with Streptococcus agalactiae has not been reported in an immunocompetent adult so far. The slow progress of tuberculous osteomyelitis, due to lack of significant elevations in the laboratory values and changes in the radiographic appearance, often leads to confusion with brodie's abscess. These two clinical conditions often lead to delay in diagnosis and progressive bone destruction. The aim of this report was to highlight recognizing the possibility of coinfections in tuberculous osteomyelitis and early treatment targeting both organisms simultaneously.

Case report: We report a case of a 24-year-old male patient from Kerala, India presented with pain and swelling over distal leg for 2 weeks along with mild fever for 1 month. Imaging showed a brodie's abscess over distal tibia. Pus culture isolated S. Agalactiae. Bone biopsy reported as necrotizing granulomatous lesion. Computed tomography thorax was suggestive of necrotic tuberculous mediastinal and hilar lymphadenopathy. Based on histopathology, microbiology, and radiological findings, coinfection of tuberculous osteomyelitis and bacterial infection was confirmed and antitubercular therapy was started, along with antibiotics for S. agalactiae.

Conclusion: Tuberculous osteomyelitis mimicking brodie's abscess is very rare. It is important to consider coinfection in osteomyelitis and it is essential to do tuberculosis-polymerase chain reaction and histopathological examination, along with bacterial and fungal culture of pus in subacute osteomyelitis for the early diagnosis and treatment.