Behçet’s disease (BD) is a multisystemic disorder characterized by recurrent ulcers of the mouth and genitalia and relapsing iritis (1). The vascular lesions encountered in BD are arterial occlusions, aneurysm, venous occlusions, and variceal development (1, 2). The disease affects both arteries and veins (3). The reported incidence of vascular involvement ranges 7% to 29% in the literatures. Bilateral pulmonary artery aneurysms are rare but recognized consequence of vascular involvement in BD (4). But to our knowledge there has been only one case who had pseudoaneurysm at internal carotid artery in the literature (5).
BD, in general occurs more commonly in men and predominately affects people in their second and third decades. The incidence of the disease is considerably higher in Turkey, Israel, Lebanon, Iran, Japan, Korea and China (1, 2). The prevalence of vascular involvement is about 25% and vascular involvement is the leading cause of death in BD(1-5). Vascular involvement is more frequent in males than in females (36% and 14%). Three forms of vascular disease (venous occlusion, arterial aneurysms and /or arterial occlusion) are found in BD. Venous lesions ( 88%) are more frequently than arterial lesions (12%). The most common site of aneurysms in BD is abdominal aorta following femoral artery, popliteal artery and pulmonary artery (1). Arterial involvement generally occurs in the late stage of the disease, usually in young men (1, 3, 4). Although pulmonary aneurysms are usually encountered in patients with BD, to our knowledge there has been no case reported more than 3 aneurysms with pseudoaneurysm formation in the common carotid artery.
In our case, we detected total 4 aneurysms at the branches of pulmonary artery. Our case was a-27 year old woman. Her dermatological symptoms were present for 2 years. A pseudoaneurysm was detected in her right common carotid artery relatively rare site and formation of involvement.
The development of aneurysm and pseudoaneurysm at arteries in BD can be explained by the pathologic process in the wall of the blood vessels. Immune complex deposition in small vessels leads to complement fixation and polymorphonuclear leukocyte activation. The neutrophil activation and perivascular infiltration in the vessel wall lead to degeneration and occlusion of the vasa vasorum. Occlusion of the vasa vasorum leads to transmural necrosis of the wall of large muscular arteries. Mild to advanced fibrinization can be seen in intima and adventitia, which may result true aneurysm formation. Ultimately perforation of the vessel wall can occur, and pseudoaneurysm formation follows(1).