Hydatid cyst fistula into the aorta.

A case is presented of fistula formation between a primary hydatid cyst and the abdominal aorta which we believe is the first in the world literature. The patient underwent surgery with a diagnosis of aneurysm of the coeliac trunk. During the operation the presence was discovered of a hydatid cyst opening into the aorta. It was dealt with by partial resection and closing of the communication. Three months later the patient was readmitted with a new bleeding episode which resulted in a fatal outcome.