Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 17 1 2022 03 14 96 100 EN Mahmut Kursat Ozsahin Orthopaedics and Traumatology Department, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey Bedri Karaismailoglu Orthopaedics and Traumatology Department, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey Cumhur Deniz Davulcu Orthopaedics and Traumatology Department, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey Erdem Sahin Orthopaedics and Traumatology Department, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey Murat Hız Orthopaedics and Traumatology Department, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey 2021 04 19 2021 12 25 We report a 44-years-old woman with cystic echinococcosis (CE) who presented with simultaneous involvement of liver and vastus lateralis muscle to Istanbul University-Cerrahpasa, Istanbul, Turkey in 2020. Although she underwent surgery for the liver, the intramuscular mass was ignored. While the patient was under post-operative albendazole treatment, she was investigated for the mass on her right thigh which was excised later. The comparison of magnetic resonance imaging before and after albendazole treatment showed that albendazole eliminated the intramuscular vesicle structures by accelerating the degeneration process of the cyst. The comparison of pathology samples sent from both liver and intramuscular CE also revealed that the albendazole has left the laminar membrane intact, degenerate the germinative membrane, thereby reducing the intra-vesicle pressure and also caused the scolex structures to disappear. To the best of our knowledge, this is the first paper to report the effect of preoperative albendazole treatment on the structure of intramuscular CE. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/3324 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/3324/1200