PURPOSE:The primary biliary carcinoma is usually unresectable at presentation, because of early lymphatic spread. To determine the incidence and the spread pattern of lymph node metastases according to the location of the primary tumor, we analyzed the CT scans of the patients with primary biliary adenocarcinome. MATERIALS AND METHODS: We reviewed the CT scans of 92 patients with pathologically proven primary biliary adenocarcinoma, including 45 peripheral cholangiocarcinomas, 22 hilar cholangiocarcinomas, 18 gallbladder carcinomas, and 7 common bile duct carcinomas. Positive adenopathy was diagnosed when the node exceeded 10 mm in short axis. RESULTS:The overall incidence of nodal metastases was 59.8 % (55/92); 66.7 % in peripheral cholangiocarcinoma, 54.5 % in hilar cholangiocarcinoma, 55.6 % in gallbladder carcinoma, and 42.9 % in common bile duct carcinoma. The most commonly involved nodal group was the lesser omentum, followed by the celiac, periaortic, and peripancreatic group. The phrenic node group was only involved in the cases with the peripheral or hilar cholangiocarci nome. CONCLUSION:The primary biliary carcinoma has a high incidence of lymph node metastases at the time of diagnosis, and shows different nodal spread pattern according to the location of the primary tumor. Involvement of the phrenic node was limited to the peripheral and hilar cholangiocarcinoma.