First case report of atrial myxoma in interauricular occlusive device in Colombia.

Introduction and importance: Primary cardiac tumors are extremely rare; myxomas are the most common benign type in adults. Although percutaneous closure of ostium secundum atrial septal defects (osASD) using occluder devices is a standard and safe procedure, the development of a cardiac mass on these devices is a rare event that requires careful differential diagnosis among thrombi, endocarditis, and neoplasms. Case presentation: A 58-year-old woman with a history of an osASD corrected percutaneously with an occluder device in 2021 presented 3 years later for routine follow-up. Transesophageal echocardiography revealed a mobile, heterogeneous, lobulated mass attached to the left atrial disk of the device. Due to the high risk of systemic embolization, surgical intervention was scheduled. A median sternotomy and atriotomy confirmed a gelatinous mass adhering to the device. The mass and the occluder were completely resected, followed by reconstruction of the interatrial septum using a bovine pericardial patch. Histopathological analysis confirmed a cardiac myxoma. The postoperative course was favorable, with complete functional recovery. Clinical discussion: This represents the first reported case in Colombia of an atrial myxoma arising from an ASD occluder device. Although rare, this complication highlights the importance of long-term echocardiographic surveillance after percutaneous cardiac interventions. Surgical resection remains the gold standard treatment to prevent embolic events and obtain a definitive histological diagnosis. Conclusion: This case describes the first Colombian report of a cardiac myxoma associated with a percutaneous interatrial closure device, emphasizing the need for a comprehensive differential diagnosis of late intracardiac masses.