[Cystic space-occupying lesion with involvement of the pelvis: unusual site of echinococcosis. Case report and surgical treatment].

A case of an unusual localization of cystic echinococcosis is presented. Initially it appeared as a retropertioneal tumor with bone involvement and the diagnosis was only recognized intraoperatively. The patient was treated by radical surgery and chemotherapy according to the guidelines of the WHO. We conclude that echinococcosis should be considered in extrahepatic cystic tumors, especially in patients from endemic areas.