[A case report of chronic traumatic thoracic aneurysm (thrombotic closure type) which appeared as a mediastinal tumor in preoperative findings].

Chronic traumatic thoracic aneurysm is considered to be an uncommon disease. A case of 59-year-old man who had a history of blunt chest trauma with a traffic accident thirty years ago is reported. He has no symptoms and no signs since the accident. The roentogenogram of his chest showed widening of upper mediastinum, but aortography did not reveal the aneurysmal dilatation of the aortic arch. CT and MRI study showed an inhomogenous mediastinal tumor simulating neoplasm neighboring the aortic arch. At surgery, it was found to be a thoracic semispherical pseudo-aneurysm (thrombotic closure type) measuring 3 cm diameter with slightly hard fibrous tissue contained aseptic brownish fluids. Following partial clamping of the aorta, the thoracic pseudo-aneurysm was opened and the direct closure of the aortic tear with teflon felt was performed. It is important to check the presence of the thoracic pseudo-aneurysm for following-up the patient after the thoracic trauma.