Sudden death of a middle-aged woman with congenital heart disease presented macroscopic and microscopic pulmonary artery aneurysm and dissection with thrombosis: A case report

A middle-aged woman with unrepaired congenital heart disease died suddenly from asphyxia due to hemoptysis. Postmortem computed tomography, autopsy, and histological examinations revealed the presence of an aneurysm and dissection of the right main pulmonary artery with intraluminal thrombus. The observed congenital heart diseases included patent ductus arteriosus, ventricular septal defect, and right-sided aorta. These anomalies predisposed her to left to right shunt, resulting not only in pulmonary artery hypertension and right ventricular hypertrophy, but also pulmonary artery aneurysm and dissection. Histological examinations confirmed the presence of medial degeneration and elastic fiber disruption, as well as muscular hyperplasia of the vasa vasorum and follicular infiltration of the lymphocytes and plasma cells in the main pulmonary artery. These changes may have contributed to the pathogenesis of the aneurysm and dissection through the induction of arterial wall fragility. Histology demonstrated, in addition to findings of pulmonary hypertension, such as plexiform lesions, medial-intimal hyperplasia, and veno-occlusive lesion, unique findings related to multiple dissections of the intra-pulmonary elastic arteries, which may have caused the lethal hemoptysis.