[Penetrating atheromatous ulcer of the thoracic aorta. Apropos of a case].

The authors report a case of penetrating atheromatous ulceration of the descending thoracic aorta complicated by a haemothorax. Atheromatous ulceration of the aorta is usually observed in elderly hypertensives. It is caused by rupture of the internal elastic layer under an atheromatous plaque extending into the media and resulting in a parietal haematoma of the aorta. Clinically, the differential diagnosis is that of a dissection of the aorta or of fissuration of an atheromatous aneurysm. Nowadays, the investigations of choice are a chest CT scan with injection of contrast and MRI. Transoesophageal echocardiography excludes dissection of the aorta but may miss a direct image of penetrating ulcer when the latter is of small size. The treatment of choice is not established because the natural history of the condition is not well known. Penetrating ulcer would seem to progress slowly to development of an aortic aneurysm. Surgery is mainly reserved for forms complicated by painful recurrences or rupture and for cases involving the ascending aorta.