“…It is responsible for supplying blood to the anterior chest wall and the breasts. 9,10 The mean diameter of this artery is small (around 2 mm), but its flow rate can reach 150 mL/min, and it can cause severe and even fatal bleeding. 11,12 The etiology of true aneurysms of the internal thoracic artery is generally related to vasculitis (Kawasaki disease, polyarteritis nodosa, and systemic lupus erythematosus), connective tissue diseases (Marfan Syndrome and Ehlers-Danlos Syndrome), type 1 neurofibromatosis, fibromuscular dysplasia, atherosclerosis, or idiopathic causes.…”