Ultrasonography as a Tool for Monitoring the Development and Progression of Cholangiocarcinoma in Opisthorchis viverrini/ Dimethylnitrosamine-Induced Hamsters

Cholangiocarcinoma (CCA) is the most common cancer in northeastern Thailand. At present, effectivediagnosis of CCA either in humans or animals is not available. Monitoring the development and progressionof CCA in animal models is essential for research and development of new promising chemotherapeutics.Ultrasonography has been widely used for screening of bile duct obstruction in CCA patients. In this study,we preliminarily investigated the applicability of ultrasonography to monitor the development and progressionof CCA in Syrian golden hamsters (n=8) induced by Opisthorchis viverrini (OV)/dimethylnitrosamine (DMN)administration. Ultrasonography and histopathological examination of hamsters was performed at week 0, 20, 24and 28 of OV infection or at the start of water/Tween-80 administration to controls. The ultrasonographic imagesof liver parenchyma and gallbladders of OV/DMN-induced CCA hamsters showed sediments in gallbladder,thickening of gallbladder wall, and hypoechogenicity of liver parenchyma cells. The ultrasonographic imagesof liver tissues were found to correlate well with histopathological examination. Although ultrasonography doesnot directly detect the occurrence of CCA, it reflects the thickening of bile ducts and abnormality of liver tissues.It may be applied as a reliable tool for monitoring the development and progression of CCA in animal modelsin research and development of new promising chemotherapeutics for CCA.