[Aneurysm of the innominate artery: pathology simulating pulmonary neoplasm]

A chance case of aneurysm of the brachiocephalic trunk suggested a review of the literature on this rare pathology. Stress is laid on the possible asymptomaticity of the lesion and on its frequent chance observation in chest X-rays; the diagnostic procedure, at times particularly complex, may not lead to decisive results but the possibility of aneurysm of the brachiocephalic trunk must be borne in mind in any case so as to avoid gross diagnostic and therapeutic errors.