Clinicopathological features and recurrence patterns of combined hepatocellular-cholangiocarcinoma

BACKGROUND: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a primary liver carcinoma with both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) components. We examined the clinicopathological characteristics and recurrence patterns of cHCC-CCA. Because of the rarity of cHCC-CCA, its etiology, clinicopathological features, and prognosis in comparison with other primary liver carcinoma remain unknown. Its recurrence pattern and sites in particular also need to be elucidated. METHODS: All patients who underwent hepatectomy for primary liver malignancies between 2005 and 2015 were retrospectively included in this study. RESULTS: Eight hundred and ninety-four hepatectomies were performed. Nineteen cases of cHCC-CCA (2.1%) in 16 patients were enrolled. Three patients underwent re-hepatectomy. The background of hepatitis viruses and tumor marker patterns of cHCC-CCA were similar to those of HCC and dissimilar to those of intrahepatic CCA (iCCA). Biliary invasion was common in cHCC-CCA and iCCA. The 5-year overall survival values of the cHCC-CCA, HCC, and iCCA patients were 44.7%, 56.6%, and 38.5%, respectively. The 5-year recurrence-free survival values of the cHCC-CCA, HCC, and iCCA patients were 12.2%, 28.7%, and 32.9%, respectively. The liver was the most common recurrence site. Unlike HCC, however, the lymph node was the second-most common recurrence site in both cHCC-CCA and iCCA. Pathological samples of the recurrent lesions were obtained in six patients, and four had cHCC-CCA recurrence pathologically. CONCLUSION: cHCC-CCA had a mixture of characteristics of HCC and iCCA. Many cases of cHCC-CCA remained cHCC-CCA pathologically even after recurrence.