Pulsatile masses are mostly suggestive of vascular lesions or closely related to blood vessels. Imaging examinations such as angiography and blood flow ultrasound can clearly localize, quantify and qualify the diagnosis, and provide detailed information about the blood supply and its relationship with the surrounding great vessels. A pulsating mass on the clavicle is the clinical manifestation of peripheral aneurysm. Peripheral aneurysms are aneurysms that occur in each main artery, such as the carotid artery and the extremity arteries. The former is usually caused by atherosclerosis, and its aneurysm wall contains the three-layer structure of the arterial wall, and may be multiple or coexist with aortic aneurysm; the latter is often secondary to arterial trauma (e.g. stabbing injury, arterial puncture), and its aneurysm wall is fibrous tissue, and is mostly solitary. Various infectious factors (e.g., infectious emboli shed during bacterial endocarditis) can also destroy the arterial wall and form so-called infected aneurysms. Diagnosis: The most important clinical manifestation is a localized pulsating mass in line with the heart beat, accompanied by distension and pain, and tremor and vascular murmurs may be detected. Depending on the location of peripheral aneurysm, each may have its own special symptoms and signs: 1. Carotid aneurysm A pulsating mass on the lateral side of the anterior neck may cause hoarseness, Horner’s syndrome, upper limb weakness, abnormal sensation and other symptoms due to compression of vagus nerve, carotid sympathetic nerve and brachial plexus nerve. If the aneurysm ruptures, it may cause bleeding or even asphyxia, and if the thrombus inside the aneurysm cavity is dislodged, it may cause intracranial artery embolism and ischemic stroke. 2.Subclavian aneurysm A pulsating mass in the supraclavicular region may be found, and the compression of the brachial plexus nerve may cause abnormal sensation and movement disorders in the upper limbs. 3.Femoral aneurysm The pulsating mass is located in the inner thigh. When the aneurysm compresses the femoral nerve, numbness and radiating pain of the lower extremity appear; when the femoral vein is compressed, swelling of the lower extremity appears; dislodged thrombus in the lumen of the aneurysm may cause acute arterial embolism of the lower extremity, resulting in pain, pallor and decreased skin temperature of the affected extremity. 4.Popliteal aneurysm may be seen as a pulsating mass in the popliteal fossa. Due to occlusion of thrombus in the lumen of the aneurysm, embolization of the distal artery by dislodged thrombus or compression by rupture and bleeding of the aneurysm, it often causes severe ischemia in the lower leg, resulting in claudication, resting pain and even necrosis.