Figure 1.

Histopathology of hepatic trematodiasis, liver, odontocetes. (A) Trematodes are present within the dilated biliary lumen, while the biliary epithelium is highly hyperplastic. Case no. 3, harbor porpoise. Hematoxylin and eosin (HE). (B) Numerous trematode eggs occlude the dilated biliary lumen. Note hemorrhage in the adjacent parenchyma. Inset, higher magnification of triangular-shaped eggs within the lumen. Case no. 9, Dall's porpoise. HE. (C) Large lymphoid follicles are formed in portal areas, while abundant bridging fibrosis dissects normal hepatic architecture. Inset, higher magnification of the reactive biliary epithelium in areas of bridging fibrosis. Case no. 4, harbor porpoise. HE. (D) Severe lymphoplasmacytic infiltration in the lamina propria of a dilated bile duct, partially effacing the hyperplastic biliary epithelium. Case no. 17, Hubbs' beaked whale. HE. (E) Severe ductular reaction replaces the hepatic parenchyma. Inset, higher magnification of proliferating bile ducts. Case no. 17, Hubbs' beaked whale. HE. (F) An island of hepatocytes remains within an area of prominent ductular reaction with fibrosis. Case no. 17, Hubbs' beaked whale. Masson's trichrome. (G) Individuals with severe fibrosis are characterized with portal-to-portal bridging fibrosis, perivenular and perisinusoidal fibrosis, and a fibrous septum formation. Inset, demonstration of intracytoplasmic inclusion-like vacuoles in hepatocytes. Case no. 13, Dall's porpoise. Masson's trichrome. (H) An island of hepatocytes is not delineated by apparent fibrous scarring, and the transition from hepatocytes to proliferative bile ducts is uninterrupted by reticular fibers, indicating a lack of apparent hepatocellular damage. Note the relatively organized hepatocyte cords. Case no. 12, Dall's porpoise. Reticulin. (I) Moderate amounts of Prussian blue-positive hemosiderin deposits are detected in Kuppfer cells. Inset, demonstration of intracytoplasmic hemosiderin also within hepatocytes. Case no. 2, harbor porpoise. Prussian blue.