Hydatid Cyst in Proximal Femur: A Case Report

Hydatid cysts, caused by the larval stage of the tapeworm Echinococcus Granulosus, are rare in the musculoskeletal system. We present a unique case of a hydatid cyst found in the proximal femur / hip joint of a patient with an implanted hip prosthesis. A 75-years old male with a history of cemented Hemi-arthroplasty (Thompson prosthesis) presented with hip pain and limited (painful) range of motion of the hip. Radiologically osteolysis was appreciated, suggestive of implant loosening. Surgical intervention was done. Per-operative cystic lesions were found. Clinical diagnosis of Hydatid disease was made and the cysts were successfully treated with Hypertonic saline and albendazole. Histopathological examination confirmed the diagnosis of Hydatid cyst. This case highlights the importance of considering Hydatid cyst as a rare, differential diagnosis in patients even with a prosthetic joint, residing especially in endemic regions of the world, which would require multidisciplinary approach for their management.