[An autopsy case of chronic pulmonary thromboembolism associated with congenital portal hypoplasty and pulmonary artery aneurysm].

A 44 year-old woman died after a history of chronic right heart failure for 25 years. Roentgenological studies showed marked pulmonary aneurysm, and hemodynamics at rest revealed severe pulmonary hypertension. The diagnosis of chronic pulmonary thromboembolism was made by MRI which identified a high intensity mass in the dilated right pulmonary artery. At autopsy, a large organized thrombus adhered to the atherosclerotic pulmonary artery, and pulmonary thromboembolism or hemorrhagic infarction were identified. Microscopic examination revealed intimal and medial proliferation in small arteries and plexiform lesions. In addition, hypoplasty of the portal vein and portacaval shunt, which were thought to be congenital, were present. It has been recognized that the portacaval shunt can be attributed to pulmonary hypertension. In this case it was considered that the main cause of pulmonary thrombus formation was both pulmonary atherosclerosis and pulmonary artery aneurysm caused by prolonged pulmonary hypertension. This is the first case of chronic pulmonary thromboembolism associated with congenital hypoplasty of portal vein.