Abstract
Echinococcosis is caused by larva of Echinococcus granulosus. Liver being most commonly involved, other organs/body parts such as bone involvement is not so uncommon, especially in cattle-raising countries such as India. Primary osseous echinococcosis remains undiagnosed until complications have developed. We report a case of complicated pelvic echinococcosis presented with left gluteal mass, acetabulum and femoral head destruction, and reduced hip mobility. Pre- and postoperative chemotherapy with albendazole and en bloc surgical removal of the cyst were advocated as the preferred option of treatment. Primary osseous echinococcosis must be kept in mind when encountering a case of chronic bony mass not responding to antitubercular therapy, and hydatid serology should be performed along with other imaging and histopathological examinations to support or confirm the diagnosis to prevent long-term complications.