Objective: To evaluate the computed tomographic (CT) appearances for differentiating of primary hepatic adenocarcinoma (peripheral, mass-forming cholangiocarcinoma) and secondary hepatic adenocarcinoma (liver metastases from colorectal carcinoma).
Material and method: Between January 2004 and December 2010, 45 patients with peripheral, mass-forming cholangiocarcinoma (Group 1) and 45 patients with liver metastases from colorectal adenocarcinoma (Group 2) who underwent abdominal CT scan at the authors' institution were included in the present retrospective study. Two experienced, abdominal radiologists blinded to the participants 'clinical histories and pathological results, separately reviewed the CT findings of each participant (number of liver mass(es), size, margin, internal calcification, hepatic capsule retraction, vascular invasion, peripheral bile duct dilatation, proximal bile duct enhancement, extrahepatic spreading, nearby lymphadenopathy and nearby organ invasion) and gave the presumed diagnosis of each individual case. Any discrepancies were solved by a consensus review. Finally, the authors conducted a stratified analysis of the patients in both groups based on their CT appearances.
Results: Ninety participants were 35 (38.9%) female, 55 (61.1%) male, age range from 43 to 88 years (mean 63.4 years, SD = 10.7). There were 28.9% vs. 48.9% female with the mean age (SD) of 61.5 (9.4) vs. 65.4 (11.6) years in Group 1 and 2, respectively. The mean size (SD) were 7.4 (3.7) cm vs. 4.0 (2.1) cm, in Group 1 and 2, respectively (p < 0.001). The presence of hepatic capsule retraction, vascular invasion, peripheral bile duct dilatation, proximal bile duct enhancement, extrahepatic spreading, nearby lymphadenopathy, and nearby organ invasion were significantly higher in Group 1 than Group 2 (p < 0.001). In contrary, the presence of multiple lesions with separated locations, and smooth margin were significantly suggested of Group 2 (p < 0.001 and p = 0.007, respectively). By logistic regression analysis, peripheral bile duct dilatation, extrahepatic spreading, and proximal bile duct enhancement were the sole predictors of peripheral, mass-forming cholangiocarcinoma. The interobserver agreement for the presumed diagnosis of liver mass was good (kappa = 0.76).
Conclusion: The presence of peripheral bile duct dilatation, extrahepatic spreading, and proximal bile duct enhancement were highly suggestive of peripheral, mass-forming cholangiocarcinoma.