Abstract: Objective The clinicopathological features of 82 cases of combined hepatocellular-cholangiocarcinoma (cHCC-CCA) were analyzed. Methods The medical records of 82 cases with cHCC-CCA were analyzed retrospectively, including 50 HCC patients and 30 CCA patients in the same period. The general clinical data and pathological data of the three groups were compared, and the pathological manifestations under cHCC-CCA microscope were analyzed. Results The onset age and AFP level in CCA group were (57.1±8.2) years old and (312.0±37.4) U/mL, and the differences were statistically significant (P<0.05) when compared with cHCC-CCA [(52.6±6.7) years old, (364.3±35.2) U/mL] and HCC [(53.0±7.0) years old, (382.4±44.9) U/mL]. However, there was no significant difference among cHCC-CCA, HCC onset age and AFP level (P>0.05). HBV infection was found in 63 patients (76.8%) with cHCC-CCA and 46 patients (92.0%) with HCC. They were significantly higher than those of CCA patients [11 cases (36.7%), P<0.05], but there was no significant difference between cHCC-CCA and HCC patients (P>0.05). In HCC group, the tumor diameter and poorly differentiated cases were (4.6±1.2)cm and 42 cases (84.0%), the difference was statistically significant (P<0.05) when compared with cHCC-CCA [(5.7±1.4) cm, 51 cases (62.2%)] and CCA [(5.5±1.6) cm, 19 cases (63.3%)]. However, there was no significant difference in tumor diameter and poorly differentiated cases between cHCC-CCA and HCC (P>0.05). In CCA group, there were 7 cases (23.3%) of cirrhosis and 11 cases (36.7%) of lymph node metastasis. Compared with cHCC-CCA [56 cases (68.3%), 7 cases (8.5%)] and HCC [41 cases (82.0%), 3 cases (6.0%)], the difference was statistically significant (P<0.05). However, there was no statistically significant difference (P>0.05) in the cases of cirrhosis and lymph node metastasis between cHCC-CCA group and HCC group. Under the microscope of cHCC-CCA, HCC(80 cases, 97.6%) and CCA(78 cases, 95.1%) were included. The HCC region showed thick trabecular cord-like and pseudoglandular structures under the microscope, with hepatocyte-like differentiation and rich eosinophilic cytoplasm, and the nucleus was round. In the CCA region, the moderately and poorly differentiated atypical glands were arranged in irregular glandular tubular and solid cord structures, accompanied by interstitial fiber tissue. In another 11 cases (13.4%), there was a cholangiolocellular carcinoma (CLC) region in the tissues. Microscopically, the glands showed a narrow cavity-like and "staghorn" growth pattern, accompanied by obvious interstitial fibrous tissue proliferation. The cells were small, the cytoplasm was sparse and basophilic, the nucleus was oval, and transparent stroma was abundant around the glands. Conclusion There are similarities and differences in clinicopathological features among the cHCC-CCA and HCC and CCA patients. Paying attention to the composition ratio of HCC and CCA under cHCC-CCA microscope may provide scientific basis for clinical diagnosis and treatment of cHCC-CCA.

Key words: Combined hepatocellular-cholangiocarcinoma, Hepatocellular carcinoma, Cholangiocarcinoma, Cholangiolocellular carcinoma