Background: The Bacillus Calmette-Guérin (BCG) is a vaccine which is widely administered in newborns to protect against tuberculosis. Although generally safe, BCG vaccination can occasionally lead to uncommon local or systemic complications, including granulomatous inflammation at sites distant from the inoculation site [1,2].

Case Presentation: A case report of a 7-month-old previously healthy male infant, presented with a firm, non-tender anterior sternal mass of three weeks’ duration. There were no systemic symptoms, No history of trauma, or no known infectious exposures. Imaging revealed a well-circumscribed soft tissue mass anterior to the sternum without underlying bony involvement. Histopathological examination following surgical excision demonstrated granulomatous inflammation, with no evidence of acid-fast bacilli or malignancy. Given the patient’s history of neonatal BCG vaccination and exclusion of alternative diagnoses, a diagnosis of BCG vaccine-associated granulomatous inflammation was made [3,4].

Management and Outcome: The patient underwent wide local excision of the mass and sent for histopathological evaluation. Postoperative recovery was uneventful. Wound was reviewed on post operative day 3 and 10. Follow up was done after 3 months.

Conclusion: This case highlights an unusual presentation of BCG vaccine-related granulomatous inflammation as an isolated sternal mass in infancy. Awareness of such rare post-vaccination complications is crucial for prompt diagnosis and appropriate surgical management to achieve complete resolution and avoid unnecessary delays in care [5].