Giant right coronary artery aneurysm mimicking a mediastinal mass: Diagnostic challenges in a rare case from a resource-limited setting

Abstract

The management of giant right coronary artery aneurysm remains challenging, particularly in patients with metabolic comorbidities and advanced heart failure. This case report was intended to describe the clinical presentation, diagnostic work-up, and management considerations in a patient with a giant right coronary artery aneurysm complicated by intraluminal thrombus formation and chronic total occlusion. A 60-year-old man with diabetes mellitus, hypertension, heavy smoking habit, and previous abdominal aortic aneurysm surgery was admitted with progressive dyspnea, orthopnea, peripheral edema, and pulmonary congestion. Acute decompensated heart failure was initially suspected. Transthoracic echocardiography demonstrated a semisolid mass compressing the right-sided cardiac chambers and severe biventricular systolic dysfunction, with a left ventricular ejection fraction of 25%. Computed tomography angiography revealed a heterogeneous mediastinal mass adherent to the pericardium and pulmonary trunk and initially raised suspicion of a right atrial aneurysm or mediastinal tumor. A definitive diagnosis was established by coronary angiography, which demonstrated a giant saccular aneurysm of the distal right coronary artery measuring 73.1×66.9 mm with contrast retention and intraluminal thrombus. Because of severe ventricular dysfunction, multiple comorbidities, and high procedural risk, invasive intervention was deferred and intensive medical therapy was selected as the initial management strategy. This case highlights the importance of comprehensive multimodality imaging, particularly coronary angiography, in distinguishing giant coronary artery aneurysm from nonvascular mediastinal lesions. In high-risk patients, careful risk stratification and optimized medical therapy may be required before surgical or percutaneous intervention is considered.