[An autopsy case of massive hemoptysis due to a rupture of the thoracic aortic aneurysm into the left lung].

An 81-year-old man was admitted to our hospital with aspiration pneumonia and thereafter suddenly died of massive hemoptysis. An autopsy revealed an aortic arch aneurysm which had ruptured into the left lung. This case showed that acute infectious lung diseases, such as aspiration pneumonia, could cause a rupture of thoracic aortic aneurysms. Thoracic aortic aneuysms are uncommom causes of hemoptysis. Their rupture into the left lung is rarer than that into other organs and not many such cases have been previously reported in the literature. Making an accurate diagnosis is also difficult if an aneurysm is not suspected. Delay in surgical treatment could result in a lethal hemorrhage. In conclusion, we suggest that thoracic aortic aneurysms should always be considered and carefully ruled out in patients who present with either massive or minor hemoptysis.