To analyze the clinical characteristics and enhancement pattern on contrast-enhanced ultrasound (CEUS) of combined hepatocellular-cholangiocarcinoma (cHCC-CC).

A total of 49 patients who were pathologically confirmed as cHCC-CC by surgery and underwent CEUS examination in Southwest Hospital Affiliated to Third Military Medical University from January 2005 to February 2015 were retrospectively enrolled. There were 3 enhancement patterns on CEUS: hepatocellular carcinoma (HCC) pattern, cholangiocarcinoma (CC) pattern and indeterminate pattern. The proportions of HCC pattern and CC pattern of cHCC-CC were compared by χ² test. And the proportions of tumour maker elevation [(alpha-fetoproteins, AFP) and/or (carbohydrate antigen, CA19-9)] in accordance or discordance with enhancement patterns were compared by χ² test.

Among the 49 cHCC-CC patients, 44 were male and 5 were female. Mean age was (52.3±9.8) years old (range: 28-74 years old). Of all cases, 41 (83.7%, 41/49) patients had single nodule. Mean size of nodule was (5.3±3.5) cm (range: 1.5-13.8 cm), and the size of 51.0% (25/49) lesions were < 5 cm. Totally 34 (69.4%, 34/49) patients had pathologically diagnosed cirrhosis. AFP elevation was found in 31 (63.3%, 31/49) patients, CA19-9 elevation was found in 12 (24.5%, 12/49) patients, simultaneous elevation of both AFP and CA19-9 was found in 9 (18.4%, 9/49) patients. The percentages of CC pattern and HCC pattern were 51.0% (25/49) and 44.9% (22/49) respectively. And there was no significant difference between the two patterns (χ²=0.368, P=0.544). In 9 patients with simultaneous elevation of both AFP and CA19-9, CC pattern was observed in 5 patients and HCC pattern was noted in 4 patients. There were 12 (24.5%, 12/49) patients with tumor marker elevation (AFP or CA19-9) in discordance with enhancement patterns on CEUS. Among the 12 cases, 9 cases with AFP elevation were CC patterns on CEUS and 3 cases with CA19-9 elevation were HCC patterns on CEUS. Simultaneous elevation of tumor makers (AFP and CA19-9) or tumor mark elevation (AFP or CA19-9) in discordance with enhancement patterns on CEUS was found in 21 (42.9%, 21/49) patients, which was significantly more than simultaneous elevation of AFP and CA19-9 alone (18.4%, 9/49) (χ²=6.918, P=0.009).

Clinical characteristics of patients with cHCC-CC were similar to that of patients with HCC. The proportion of HCC pattern and CC pattern was comparable. Combination of test of tumor makers (AFP and CA19-9) and enhancement pattern on CEUS maybe helpful for the diagnosis of cHCC-CC.