Diagnosis of primary hydatid cyst of thigh by fine needle aspiration cytology.

Hydatidosis is a parasitic infestation caused by larval form of the tapeworm, Echinococcus granulosus. Primary hydatid cyst in the skeletal muscles and subcutaneous tissue of thigh without involving thoracic and abdominal organs is an exceptional entity, even in countries where the Echinococcus infestation is endemic. We report an unusual case of primary hydatid cyst of thigh in proximity to skeletal muscles. This case illustrates that echinococcal disease should be considered in the differential diagnosis of every subcutaneous cystic mass. This case is presented here for its rarity.