Intrahepatic bile duct dilatation secondary to hepatocellular carcinoma: CT features in 10 patients

Background: To determine the computed tomographic (CT) features of bile duct obstruction secondary to hepatocellular carcinoma (HCC).Methods: CT examinations of 10 patients (mean age, 58 years) with bile duct obstruction secondary to HCC were retrospectively reviewed.Results: All tumors were intrahepatic. Eight tumors were well-delineated and two were ill-defined. The largest diameters of tumor ranged from 1.5–6.0 cm (mean, 3.6 cm). All tumors were hypodense before contrast and did not contain calcification. After contrast, four tumors became hypodense, three were isodense, and three were hyperdense to the liver. No tumor demonstrated encapsulation. Diffuse intrahepatic bile duct dilatation was observed in seven patients. One patient had extrahepatic bile duct dilatation. Localized bile duct dilatation was observed in three patients, in the hemi-liver which contained the tumor. No tumor invaded the portal vein.Conclusion: Although rare, HCC should be included in the differential diagnosis of bile duct obstruction. This diagnosis should be suggested in patients with bile duct obstruction when CT shows an associated intra- or extrahepatic mass. Our results suggest that HCC responsible for bile duct obstruction is remarkable for the absence of encapsulation.