Cholangiocarcinoma at the hepatic hilus: sonographic findings.

OBJECTIVE: This study was performed to characterize sonographic findings in patients with cholangiocarcinoma at the hepatic hilus and to compare those sonographic findings with surgical and pathologic findings. MATERIALS AND METHODS: Thirty-nine consecutive patients with hilar cholangiocarcinoma (Klatskin tumor) had preoperative color and spectral Doppler sonography and had surgical-pathologic correlation. Biliary drainage catheters were present in 24 patients (62%). In all patients, we evaluated presence of bile duct mass, level of bile duct involvement, patency of portal veins, and hepatic mass lesions. RESULTS: Ductal masses were revealed by sonography in 34 patients (87%). Masses were isoechoic in 22 patients (65%), hypoechoic in seven (21%), and hyperechoic in five (15%). The masses included nodular mural thickening in 19 patients (56%), infiltrative lesions in nine (26%), and intraductal polypoid masses in six (18%). The extent of bile duct involvement was revealed sonographically in 34 cases (87%) by the distribution of bile duct obstruction, the location of a ductal mass, or both. Portal vein involvement by tumor was shown sonographically in 20 patients (51%); 13 patients had occluded portal veins, and seven had encased portal veins without occlusion. Twenty-one portal veins in 16 patients were found to be involved at surgery; sonography showed 18 (86%) of 21 involved portal veins. Hepatic masses were present at surgery in six patients; four of these masses were malignant and two were benign. Sonography revealed five of the six masses and failed to reveal metastases in one patient who had pneumobilia from a biliary drainage catheter. CONCLUSION: Although Klatskin tumors are usually isoechoic, they can be revealed by sonography, and their morphology can be characterized. The extent of bile duct involvement may be shown on sonograms by the location of tumor and the distribution of bile duct obstruction. Portal vein involvement is frequent, and hepatic metastases are uncommon.