[Lung Cancer Associated with Atrial Septal Aneurysm Detected on Preoperative Echocardiogram].

We herein report a case of 71-year-old man who was diagnosed as right lung cancer associated with atrial septal aneurysm (ASA). ASA was incidentally detected on transthoracic echocardiography as a routine preoperative examination. Although upper lobectomy was performed without any postoperative event in this case, generally care must be taken for important comorbidity of cerebral infarction as a potential source of systemic thromboembolism both in pre- and post-surgery.