From Giant Coronary Aneurysm-related Acute Coronary Syndrome to the Diagnosis of Behçet’s Disease

Behçet's disease is a multisystemic vasculitis that rarely involves the coronary arteries. This case report presents a 19-year-old female with no traditional cardiovascular risk factors, who was admitted with acute chest pain. Electrocardiography revealed inferior ST-segment elevation myocardial infarction, and emergent coronary angiography demonstrated giant aneurysms involving all three major coronary arteries, along with total occlusion of the distal right coronary artery. Despite percutaneous interventions and thrombolytic therapy, distal flow was not restored. Extensive diagnostic evaluation was performed to identify underlying systemic causes. Differential diagnoses such as Kawasaki disease, lupus, Takayasu arteritis, polyarteritis nodosa, immunoglobulin G4-related disease, and infectious vasculitides were systematically excluded. Mucocutaneous findings, including multiple aphthous ulcers and hyperpigmented plaques, combined with vascular involvement, led to the diagnosis of Behçet's disease based on the International Study Group criteria. The patient was treated with intravenous cyclophosphamide followed by maintenance therapy with infliximab. Due to the extensive and diffuse nature of the aneurysms, surgical intervention was not pursued. Oral anticoagulation was maintained long term. During a four-year follow-up period, no new cardiac events occurred, and inflammatory markers remained well-controlled. This case underscores the importance of considering systemic vasculitides, particularly Behçet's disease, in young patients presenting with acute coronary syndrome without conventional risk factors. Early diagnosis and appropriate immunosuppressive therapy are critical in preventing life-threatening cardiovascular complications in such rare presentations.