Abstract
An asymptomatic 72-year-old female presented with a slight elevation of the γ-GTP level during a medical checkup. She was referred to the hospital due to the dilation of the left intra-hepatic bile duct and a hyperechoic tumor in the left hepatic duct were demonstrated by abdominal US. CT and ERC showed a tumor measuring 25mm in size which was mildly enhanced by a dynamic study at a site 8mm from the confluence of the bilateral hepatic ducts in the left hepatic duct. The tumor demonstrated a low intensity on T1-weighted images and high intensity on the T2-weighted and diffusion-weighted images of MRI. A left hepatic lobectomy including the left caudate lobe was performed under a diagnosis of hilar cholangiocarcinoma. The histopathological examination revealed a papillary adenocarcinoma infiltrating into the fibromuscular layer of the bile duct without regional lymph node metastasis and this case was classified as stage IA according to TNM classification (UICC). This case is herein reported because ultrasonography should be performed to detect cholangiocarcinoma for cases with a slight elevation of biliary enzymes, though non-icteric early hilar cholangiocarcinoma are not rare.
