Incidental left atrial appendage aneurysm with suspected left ventricular fistulous communication in a patient with metastatic non-small cell lung cancer

Abstract

Left atrial appendage aneurysm (LAAA) is a rare cardiac abnormality, usually identified incidentally or after complications such as arrhythmia, thromboembolism, or hemodynamic compromise. We report the case of a 63-year-old woman in whom a markedly dilated left atrial appendage was discovered incidentally during staging investigations for suspected malignancy. Cross-sectional imaging and transthoracic echocardiography demonstrated a large aneurysmal structure adjacent to the left atrium, with bidirectional flow between the left ventricle and the aneurysm, raising suspicion of a fistulous communication. Further imaging also confirmed stage IV non-small cell lung carcinoma with metastatic disease, together with a complex enlarging ovarian mass. In view of the patient’s advanced malignancy, absence of cardiac symptoms, and limited life expectancy, a conservative management strategy was adopted following multidisciplinary discussion. This case highlights the diagnostic complexity of incidental cardiac findings in patients with multimorbidity, the importance of multimodality imaging in defining rare structural abnormalities, and the value of multidisciplinary decision-making in aligning treatment with overall prognosis.