[A case of miliary tuberculosis complicated by a tuberculous aneurysm of the thoracic aorta].

An 85-year-old woman was admitted to our hospital with the chief complaint of fever. Antibiotics were not effective and a chest computed tomography scan revealed a diffuse micronodular shadow and thoracic aortic aneurysm. Subsequently, a bronchoscopy sputum culture was positive for Mycobacterium tuberculosis. Two months after the initiation of chemotherapy, the thoracic aortic aneurysm enlarged despite the improvement in lung findings. Tuberculous aneurysms are quite rare, but can be critical and acute. Therefore, caution should be exercised when treating such patients.