A thoracic aortic aneurysm is a rare entity of tertiary syphilis in the era of antibiotics. The diagnosis of the aortic aneurysm due to tertiary syphilis may be challenging due to deceptive clinical presentation and rarity of the disease in the western world. We report the case of a 59-year-old man, who presents with worsening shortness of breath and was found to have a large ascending aortic aneurysm on computed tomography angiogram (CTA) of the chest. Further workup demonstrated a positive syphilis test. Untreated earlier stages of syphilis attribute to the development of the ascending aortic aneurysm. The patient was medically treated with IV penicillin and underwent surgical repair of the aortic aneurysm. Histopathology confirmed the diagnosis of syphilitic aortitis. Tertiary syphilis often presents several years after initial infection and usually after a latent phase, making it difficult to diagnose. Syphilitic aortic aneurysms may result in a high mortality rate in untreated patients. Therefore, a high index of suspicion is required for the early recognition of a syphilitic aortic aneurysm. Early treatment with antibiotic therapy and surgical repair of syphilitic aortic aneurysms can prevent life-threatening complications.
