Table 2

Cyst characteristics of the various Echinococcus species

Nature of larval form in humansCyst components
E. granulosus Cystic, unilocular, expansileMetacestode has endocyst (internal germinal layer), exocyst (parasite-derived acellular laminated layer) and pericyst (host-derived adventitial layer)
E. multilocularis Multilocular, infiltrativeVery thin laminated layer only and no pericyst, which enables tissue invasion
E. vogeli E. oligarthrus Polycystic, expansileLarge cysts with multiple vesicles are separated by septa lined with germinal epithelium; externally, cyst is surrounded by fibrous tissue