Abstract: | Ultrasonographic examinations were carried out on four patients who had a total of six hydatid cysts. Three different patterns of cyst structure were recognized. These patterns are simple cyst, cyst with non-specific complex internal structure, and a “cyst within a cyst” pattern. The latter pattern depicting a daughter cyst within the primary cyst is thought to be a distinctive feature of echinococcal cysts, if not specific for them. Recognition of the cyst within a cyst pattern should permit a reasonably confident Ultrasonographic diagnosis of hydatid disease. |