Response patterns of adventitial layer of CE cysts. A, D Pattern I, fibrosis is found between inflammatory reaction and organ tissue. B, F Pattern II, fibrosis is found between the laminated layer and organ tissue, and no obvious inflammatory reaction is present. C, G Pattern III, fibrosis is found between the laminated layer and inflammatory reaction. D, H Pattern IV, there is diffused fibrosis within the inflammatory reaction. LL = Laminated layer, IR = inflammatory reaction, OT = organ tissue, F = fibrosis. A, B, C, D = Van Gieson stain. E, F, G, H = Haematoxylin–eosin stain. Size bar: 200 µm. CE = Cystic echinococcosis.