Hydatid cyst of the pterygopalatine-infratemporal fossa.

Hydatid disease is caused by the parasitic tapeworm. Echinococcus. This parasite in larval stage can thrive in many parts of the body, most commonly in the liver and the lung. Hydatid disease in the head and neck region is rare. An unusual location for hydatid disease in the pterygopalatine fossa-infratemporal fossa is presented. The patient did not have evidence of any other cyst on a ten-year follow-up.