Histological confirmation of periductal fibrosis from ultrasound diagnosis in cholangiocarcinoma patients Nittaya Chamadol* · Chawalit Pairojkul* · Narong Khuntikeo · Vallop Laopaiboon · Watcharin Loilome · Paiboon Sithithaworn · Paungrat Yongvanit Published online: 13 January 2014 © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery Abstract Cholangiocarcinoma (CCA) has no specific clinical signs and symptoms and non-specific bio- and tumor-markers in the early disease stage. Usually patients present to tertiary care with advanced disease stage. In order to detect early cases of CCA that may present as a mass, dilatation of intrahepatic duct or combination, ultraso- nography is accepted as a powerful imaging tool. A smaller mass or bile duct segmental dilatation requires further imaging for characterization, including computerized tomography (CT) or magnetic resonance imaging (MRI). We examined whether liver echo pattern was correlated with high risk for CCA in an endemic area of Opisthorchis viverrini (Ov). Ov infestation caused chronic inflammation of the biliary tree by periductal fibrosis (PDF), which may subsequently lead to CCA development. In our study, a World Health Organization classification of pattern of increased periportal echo (IPE) for schistosomiasis was applied. Two CCA patients gave consent for operation. Histopathological diagnosis showed both had cholangi- ocarcinoma with periductal fibrosis of the non-tumorous area of the liver. Ultrasonography was used to compare the non-tumorous area with parenchymal echo pattern and was shown to have an early CCA detection role and a surveil- lance role in an endemic area of Ov by detection of PDF. Keywords Cholangiocarcinoma · Increased periductal echo · Periductal fibrosis · Ultrasonography diagnosis Introduction Cholangiocarcinoma (CCA) is a tumor arising from the intra- or extra-hepatic bile duct epithelium. The tumor is the second most common primary liver cancer worldwide after hepatocellular carcinoma (HCC), estimated at about 3% of all gastrointestinal tract cancers [1]. Risk factors of CCA are parasitic infestation, primary sclerosing cholangitis, biliary duct cyst, hepatolithesis and toxins. Thailand has the highest incidence of CCA worldwide with incidence of 115:100,000 in men and 50 per 100,000 in women. Parasitic infestation is an important risk factor for CCA in Thailand, especially in the northeast, which corresponds to the endemic area of the liver fluke, Opisthorchis viverrini (Ov) [2]. Humans are incidental hosts in the life cycle of Ov who become infected by ingesting metacercariae of the parasite in freshwater fish. The parasite inhabits the biliary system for decades whereupon they may cause chronic inflamma- tion of the bile ducts and periductal fibrosis (PDF), which may subsequently lead to the development of CCA [3, 4]. N. Chamadol (*) · V. Laopaiboon Department of Radiology, Faculty of Medicine, Khon Kaen University, 123 Mitraparb Road, Khon Kaen 40002, Thailand e-mail: nittayachamadol@yahoo.com C. Pairojkul Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand N. Khuntikeo Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand W. Loilome · P. Yongvanit Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand P. Sithithaworn Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand N. Chamadol · C. Pairojkul · N. Khuntikeo · W. Loilome · P. Sithithaworn · P. Yongvanit Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand *These authors contributed equally to this work. J Hepatobiliary Pancreat Sci (2014) 21:316–322 DOI: 10.1002/jhbp.64 TOPIC