ABSTRACT
Hydatid cyst is usually located in the liver and lungs, rare cases showing localization in other organs or tissues. In the unusual location, echinococcosis is an excluding diagnosis that is established only after microscopic evaluation. Our first case occurred in a 67-year-old female previously diagnosed with pulmonary tuberculosis and hospitalized with persistent pain in the hip joint. The clinical diagnosis was tuberculosis of the joint, but the presence of the specific acellular membrane indicated a hydatid cyst of the synovial membrane, without bone involvement. Fewer than 25 cases of joint hydatidosis have been reported in literature to date. In the second case, the intramural hydatid cyst was incidentally discovered at autopsy, in the left heart ventricle of a 52-year-old male hospitalized for a fatal brain hemorrhage, as a result of rupture of an anterior communicating artery aneurysm. The conclusion of our paper is that echinococcosis should be taken into account for the differential diagnosis of cystic lesions, independently from their location.