RESUMEN
Hydatid disease is caused by an infestation with the tapeworm Echinococcus. Each parasite can produce thousands of eggs with oncospheres that can migrate to the liver or lungs and rarely to other sites, including muscles. The aim of this case study is to describe a rare case of a patient with an atipical hydatid cyst location and to raise awareness of this condition. We present the case of a 28-year-old female patient admitted in our clinic with a lump in her right calf who underwent surgical excision, hydatid cyst being suspected due to the aspect of the thin cyst wall membrane, confirmed by hystopathological examination. The post-operative course was uneventful and the patient was discharged five days later with medical treatment with albendazole. In conclusion, hydatid disease must be kept in mind as a differential diagnosis when facing a muscle cystic mass, even though it is very rare, and a good medical and surgical management may determine a permanent cure.