Giant Right Coronary Artery Aneurysm Mimicking a Mediastinal Cyst With Compression Effects: A Case Report

INTRODUCTION: Giant coronary artery aneurysm is an extremely rare form of coronary artery disease. The most common cause of coronary artery aneurysms is atherosclerosis. Although it is usually asymptomatic, it may have various clinical presentations, including angina, myocardial infarction or sudden death. CASE PRESENTATION: A 32-year-old woman presented with edema of the upper and lower limbs, palpitation, and chest pain, and was diagnosed with a giant right coronary artery aneurysm that had initially mimicked a mediastinal cyst. Although computed tomography (CT) suggested a mediastinal cyst, trans-thoracic echocardiography revealed an extra pericardial cyst. The definitive diagnosis of right coronary artery aneurysm was made based on CT angiography and coronary angiography findings. As treatment, aneurysmectomy was performed, and she was discharged on the sixth postoperative day with good general health condition. CONCLUSIONS: Coronary artery aneurysm should be a differential diagnosis in cases of mediastinal cyst and mass lesion.