An adult female was admitted for emergency surgery of a massively bleeding suspected aneurysm of the descending aorta. It proved to be a rupture of an aneurysm of a nonpatent ductus arteriosus or ductal diverticulum, a very rare lesion that is usually diagnosed on post-mortem. Adhesion of a previous ipsilateral lobectomy contributed to her survival. The aneurysm was resected.
Keywords: ductus arteriosus aneurysm.