A 63-year-old Saudi man, known to be hypertensive, was referred from the local hospital for further management of a markedly dilated aortic arch. He had occasional chest pain, shortness of breath, and a dry cough with no hemoptysis. He reported a history of fever, night sweats, anorexia, and a weight loss of 8 kg over 4 months. There was no history of tuberculosis before, or contact with, patients with tuberculosis. A few months earlier, he was told that he had an aortic aneurysm, but had declined surgery. His temperature was 37.4 C, blood pressure 120/80 mm Hg, respiratory rate 20/min, and his pulse rate was 100/min. His body weight was 65 kg. He had no lymphadenopathy or signs of heart failure. Laboratory results showed a WBC of 5.0 x 109/L, hemoglobin 140 gm/L, and platelets of 123 x 109/L. Urinalysis and renal, hepatic, lipid, and coagulation profiles were normal. Chest x-ray revealed a huge aneurysm of the aortic arch bulging into the left lung. The descending aorta had mild-to-moderate ectasia and tortuosity. There was bilateral pleural effusion and the cardiac size was normal. Echocardiography showed a dilated aortic arch at the junction of the descending thoracic aorta and pericardial effusion. Computed tomography of the chest confirmed the huge focal dilatation of the aortic arch measuring 9 centimeters with mural thrombosis, pericardial effusion and a few calcified and enlarged mediastinal lymph nodes. Serology for human immunodeficiency virus and syphilis was non-reactive. The patient underwent surgical resection of the aneurysm and interposition of a tube graft through a postero-lateral thoracotomy approach. Intra-operatively, gross examination of the aorta revealed a huge aneurysm involving the arch as well as the proximal part of the descending aorta, another aneurysm in the middle of the descending thoracic aorta, a thickened pericardium and pleural nodules. The thoracic aneurysm was replaced from the arch down to the descending aorta. Histopathology from tissues of the aortic aneurysm, pericardium, and lymph nodes showed a granulomatous disease with central necrosis suggestive of tuberculosis. All smears were negative for acid-fast bacilli. Antituberculosis chemotherapy was started on the first postoperative day in the form of isoniazid, rifampin, pyrazinamide, ethambutol and vitamin B6. Specimens from the tissue of the aortic aneurysm, the pericardium, the lymph nodes, the tracheal aspirates, and pleural tissue grew Mycobacterium tuberculosis sensitive to isoniazid, rifampin, pyrazinamide, and ethambutol. The subsequent course was notable for excellent tolerance and adherence to antituberculosis agents. Pyrazinamide and ethambutol were discontinued after the first two months. The patient reported general improvement in his well-being, he gained weight, and had resolution of radiological findings on subsequent imaging. Repeat computed tomography of the chest and echocardiography revealed no aortic dilatation. Isoniazid and rifampin were continued for a total of 18 months. Three months after discontinuing isoniazid and rifampin, the patient was feeling well and gained 3 further kilograms. Ten months later, the patient had sudden onset chest pain and collapsed. He had very low blood pressure in a local hospital. Immediate computed tomography of the chest showed hemothorax. The patient died soon thereafter. No post-mortem was performed.