Mycobacterium tuberculosis confined to the heart: a case report of presumed isolated myopericardial involvement

Introduction and importance: Tuberculous myopericarditis represents a rare and diagnostically challenging manifestation of tuberculosis, even in endemic regions. Delayed recognition can precipitate severe, life-threatening complications, including fulminant myocarditis and constrictive pericarditis. Early identification is therefore crucial for improving outcomes. Case presentation: We describe a 48-year-old woman who presented with progressive dyspnea, pericardial effusion, and left ventricular systolic dysfunction. Despite the absence of microbiological or histopathological confirmation, the diagnostic impression was supported by a positive QuantiFERON-TB Gold test and cardiac magnetic resonance imaging that demonstrated features compatible with probable tuberculous myopericarditis. Empirical anti-tuberculous therapy combined with adjunctive corticosteroids resulted in substantial clinical improvement and normalization of echocardiographic parameters. Clinical discussion: This case highlights the inherent complexity of diagnosing tuberculous myopericarditis, especially in resource-limited settings where access to advanced imaging may be constrained. In such contexts, diagnosis often relies on integrating clinical suspicion, immunological testing, and supportive imaging findings. Given the potential for rapid deterioration, early empirical treatment may be warranted even in the absence of definitive microbiological evidence. Conclusion: Tuberculous myopericarditis should be considered in patients presenting with unexplained myopericardial involvement in endemic areas. When confirmatory tests are unavailable or inconclusive, clinicians should rely on clinical judgment and ancillary investigations to initiate timely therapy and prevent irreversible or fatal complications.