An 89-year-old man with asthma and left pleural effusion due to lung cancer experienced recurrent syncope triggered by coughing or postural changes approximately 3 weeks prior to his visit. A comprehensive evaluation, including blood tests, electrocardiography, echocardiography, and head computed tomography (CT), was performed, revealing no specific findings related to syncope. Incidental thoracoabdominal CT revealed a large, 25-cm liver cyst compressing adjacent structures, notably the inferior vena cava (IVC)