Cardiac papillary fibroelastoma in an unusual left atrial location in combination with mediastinal thymic cyst: a case report.

BACKGROUND: Cardiac papillary fibroelastomas are rare, benign endocardial tumors most commonly found on cardiac valves. Non-valvular locations, particularly the posterior left atrial wall, are exceptionally uncommon. Thymic cysts are also rare lesions. The presence of these two non-homologous tumors in a single patient has not been previously documented. CASE PRESENTATION: This report presents a case of cardiac papillary fibroelastoma located on the posterior left atrial wall coexisting with a thymic cyst in the anterior mediastinum, both of which were incidentally detected and surgically treated. CONCLUSION: This is the first reported case of a cardiac papillary fibroelastoma arising from the posterior left atrial wall coexisting with a thymic cyst. Despite their benign nature, such lesions carry potential clinical risks. Their simultaneous detection and successful surgical management highlight the value of comprehensive imaging and multidisciplinary care.