Comparison of Imaging and Clinically Relevant Features of Combined Hepatocellular Carcinoma and Cholangiocarcinoma with Hepatocellular Carcinoma

BACKGROUND: The aim of this study was to compare the clinical, imaging, pathological, and prognostic characteristics of combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) and hepatocellular carcinoma (HCC). MATERIAL/METHODS: Medical records of 21 patients with cHCC-CC and 21 patients with HCC were retrospectively reviewed. Patients underwent a computed tomography (CT) examination within 1 month before surgery and did not receive preoperative interventional therapy. Clinical, imaging, pathological, and prognostic characteristics of cHCC-CC and HCC were compared. RESULTS: On multi-phase contrast-enhanced CT, cHCC-CC could be differentiated from HCC based on the presence of a pseudocapsule (p<0.0001; χ(2)=14.538) and extensive necrosis (p=0.009; χ(2)=8.400). The changes in the arterial phase and venous phase (V>A) and arterial phase and delayed phase (D>A) of CT enhanced scanning in HCC and cHCC-CC were statistically significant (both p<0.0001, χ(2)=28.560 and 25.846). Immunohistochemistry showed more HCC were positive for VEGF (P=0.012, χ(2)=7.785). A Kaplan-Meier survival analysis showed no statistically significant difference in progression-free survival (PFS) after treatment between patients with cHCC-CC and those with HCC (p=0.526). CONCLUSIONS: Multi-phase contrast-enhanced CT may be useful for preoperative diagnosis of cHCC-CC in tumors with a diffuse boundary, no pseudocapsule, extensive necrosis (>50%), and a dilated bile duct, and when the CT value in the delayed phase is higher than in the arterial phase. VEGF expression is more likely to be positive in HCC than cHCC-CC. There was no significant difference between cHCC-CC and HCC in prognosis, but cHCC-CC was more likely to recur after treatment than HCC.