[Pterygoïdien hydatid cyst].

INTRODUCTION: The cervico-facial hydatid cyst is rare. It accounts for 1% echinococcisis locations and usually involves the salivary gland and the thyroid. Pterygoid muscle involvement is exceptional. CASE REPORT: We report the case of a patient presenting a hydatid cyst of the pterygoid muscle. The patient presented a non specific progressive tumor syndrome. DISCUSSION: This case illustrates the importance of CT scans. Surgery is always required. We emphasize the risk of complications when the diagnosis is missed.