Hydatid Cyst of the Biceps Femoris Muscle (a Rare Case in Orthopedic Surgery)

Hydatid cysts are endemic zoonosis in iran. they may involve various organs of body. hydatid cyst in musculoskeletal system is rare and constitutes 1% to 4.5% of all cases. usually, the hydatid cyst in muscle present as a benign soft tissue tumor. the commonest clinical presentation is an asymptomatic slow growing mass. we report this rare case from orthopedic surgery center in a university teaching hospital at north iran. the literature review and mode of diagnosis has been discussed through this case report.