Adventitial layer histological features. Histological sections of the adventitial layer of cattle ECs with different features. A Laminated layer disorganization. B Necrosis between the laminated and adventitial layers. C Calcifications. D Host cells in the germinal layer. E Giant multinucleated cells. F Palisading macrophages. G Lymphoid follicles. H Eosinophils. Arrows mark indicated feature. Stain: haematoxylin and eosin. EC: Echinococcus cyst.