Tuberculous aneurysms of the descending thoracic aorta: report of a case with fatal rupture.

Tuberculous aortic aneurysm is a rare disease entity. The majority of affected patients succumb to perforation and exsanguination. The only chance for survival and cure is by resection and prolonged antituberculosis chemotherapy. Our case illustrates the high risk of rupture of tuberculous aortic aneurysms. Post-mortem examination revealed that the mechanism of aneurysm formation was by direct caseous involvement of the descending thoracic aorta from a juxtaposed left upper lobe parenchymal tuberculous process. Our findings also favor the concept that miliary dissemination (in the presence of tuberculous aortic aneurysm) is the result rather than the cause of the tuberculous aortic process.