Behçet disease is a sort of systemic vasculitis characterized by oral and genital ulcers as well as uveitis of the eye. Thoracic manifestations of Behçet disease include multiple bilateral pulmonary artery aneurysms that are of fusiform or saccular type and usually involve the main pulmonary artery or its descending branch. SVC obstruction developed secondary to inflammation of the vessel wall that led to thrombosis. Collateral pathways developed to bypass the thrombosed SVC ¹.