Mycotic tuberculous aneurysm of the thoracic aorta.

Tuberculous mycotic aneurysm has been reported with surprising frequency, especially in the aorta. Because the diagnosis can often be made on clinical and roentgenologic grounds, and because of the very poor prognosis if untreated and surgical curability if recognized, experience with three cases is reported. The aneurysm is generally of the false variety, representing a walled-off perforation of the aorta. Contiguous tuberculosis in the form of lymphadenitis or Pott abscess is generally responsible for the aortic involvement that results in the aneurysm. Miliary tuberculosis, which is often present, is probably a result rather than the cause.