Giant Right Atrial Appendage Aneurysm with Thrombus Causing Cardiac Compression in Pulmonary Tuberculosis

Right atrial appendage aneurysm (RAAA) is a rare cardiac anomaly, predominantly considered congenital, resulting from dysplasia or localized absence of atrial myocardium leading to thinning and aneurysmal dilation. However, this case highlights the possibility of an acquired mechanism, particularly in the context of chronic infectious and inflammatory conditions such as tuberculosis (TB), which may have contributed to aneurysm formation in this patient. The patient's presentation with the left-sided chest pain and weight loss in the setting of active pulmonary TB raises clinical suspicion of an infectious etiology contributing to atrial wall weakening. Histopathological examination of the excised aneurysmal wall and thrombus was instrumental in confirming the diagnosis and etiopathogenesis. Surgical excision of the aneurysm and thrombus remains the cornerstone of management in symptomatic or complicated RAAA, particularly with chamber compression or thromboembolism risk. In this patient, postoperative recovery was uneventful, and continuation of anti-tubercular therapy was crucial to eradicate residual infection and prevent recurrence. Serial follow-up demonstrated no residual aneurysm or thrombus, stable right atrial and ventricular dimensions, and preserved cardiac function. The patient remained symptom-free without arrhythmias or embolic events, underscoring the importance of vigilant postoperative surveillance. This case not only broadens the differential for RAAA etiology to include infectious causes like TB, but also highlights the integral role of histopathological diagnosis and sustained postoperative monitoring for optimal patient outcomes.