In the can expand to a large size. Their wall is made of a thick cuticle with an inner layer of proliferation of the parasite, protoscolices, small cysts containing scolices which, like granules fall in the lumen full of liquid and may form daughter cysts. The scolices contain suckers and hooklets which can be seen under the microscope. Rupture of the cyst will disseminate the infection and may result in a serious anaphylactic shock. Dogs that eat the cysts will develop the terminal form of the worm in their intestine.
Diagnosis is made by serology.
Treatment consists of surgical removal of the intact cyst. A more aggressive variant of echinococcosis is produced by Echinococcus multilocularis. The terminal host is the fox and the intermediate hosts are rodents. The cysts are multiple and smaller. Humans can contract it.