Lee M, et al. - Because hepatic artery thrombosis (HAT) following orthotopic liver transplantation (OLT) may cause hepatic parenchymal necrosis and ischemic cholangiopathy, researchers are examining additional histological characteristics that may suggest HAT in post-OLT liver specimens. Lobular necrosis, portal inflammation, ductular reaction, lobular cholestasis, and bile-tinged macrophages were common histologic findings in HAT. Lobular necrosis, hemorrhage, ductular cholestasis, and bile-tinged macrophages were more common in resection than biopsy specimens. Lobular necrosis was more common in early HAT, and late HAT was more common in ductular reaction and bile in veins. According to findings, histological changes in HAT vary depending on the type of specimen and if HAT is early or late. In late HAT, biliary injury may occur after prolonged ischemia, resulting in necrosis of the bile duct, bile in the veins, and remodeling (eg, ductular reaction). Bile in veins is an unusual finding in HAT, although it can be seen from other causes in bile infarcts.