Giant right coronary artery aneurysms presenting as a cardiac mass

INTRODUCTION Coronary artery aneurysm (CAA) is defined as coronary dilatation which exceeds the diameter of the normal adjacent artery segments or the diameter of the patient's largest coronary artery by 1.5 times. The incidence of giant CAA is difficult to be determined, since only few reports have been described in the literature. METHODS AND RESULTS A 65-year-old man was referred to our hospital because of a "mass" in the right heart detected on echocardiography at a regular medical health examination, while he experienced no any symptoms. Coronary angiography showed the severe stenosis of the left anterior descending artery (LAD) and the left circumflex artery (LCX) and the diffusely ectatic change of the right coronary artery (RCA), but no mass was found in any of these arteries. Coronary computed tomography angiography (CTA) confirmed that the "mass" was the giant aneurysms of RCA with thrombus. He received coronary artery bypass graft (CABG) with thrombectomy. The histopathology showed the deposits of lipid and hyalin in the tunica intima, the focal calcifications, the very thin tunica media, and the disappearance of the part of the tunica media in the RCA. CONCLUSIONS Coronary artery aneurysm which may contain thrombus can complicate a diagnostic coronary angiography due to the risk of distal embolization and may lead to myocardial infarction. This case report demonstrates 2 RCA aneurysms with a thrombus presenting as a giant "mass" which was successfully treated by CABG with thrombectomy.