2222 Primary Combined Hepatocellular Carcinoma-cholangiocarcinoma: A Case Report for Under-Diagnosed Primary Liver Cancer

Abstract

INTRODUCTION: Combined hepatocellular carcinoma- cholangiocarcinoma (HCC-CC) was first classified in 1949 by Allen and Lisa et al. It composes less than 1% of primary hepatic malignancies. HCC-CC is being increasingly identified given the advances in immunohistochemistry (IHC) techniques. Due to its rarity, there are no formal treatment guidelines. However, a national cancer database review reported a worse prognosis. CASE DESCRIPTION/METHODS: A 73-year-old man with history of alcohol dependence presented with 2-week history of sharp right upper abdominal pain (RUQ). Review of systems was negative. Examination revealed RUQ tenderness. Hepatitis B and C serology were negative. Abdominal ultrasound showed two heterogeneous, hypoechoic liver lesions. Abdominal MRI showed enhancing masses in the left and right liver lobes. CT-guided liver biopsy confirmed the diagnosis of HCC -CC. The left sided tumor was treated with yttrium 90 radioembolization. Unfortunately, his restaging MRI showed progressive enlargement of the right hepatic lobe tumor and complete venous thrombosis of the portal vein. With rapidly worsening performance status, he was not a candidate for any further treatment and was enrolled in hospice care. DISCUSSION: HCC-CC is a primary liver tumor which presents diagnostic challenges to the pathologist, radiologist and clinician. Adequate tissue sampling is crucial to capture enough tumor to allow recognition of both histologies. Hence, core needle sampling would be preferable to fine needle aspiration. Triphasic CT/ MRI imaging may have characteristics of either tumor type. Tumor markers are often discordant with the imaging findings, which should raise suspicion for this entity. Histology and IHC are the only definitive way to establish diagnosis, which reveal a spectrum from both histologies occurring independently yet concurrently in the liver, to mixed cells of both histologies in same lesion to a fibrolamellar HCC like histology. Notably, the World Health Organization histological classification does not have prognostic or treatment impact. Although the prognosis of HCC-CC tends to be worse than both HCC and CC, there is uncertainty if it should be treated more like HCC or CC. Surgical resection and liver transplantation are the only curative option. For resected patient, survival was substantially worse than those with HCC. Inoperable patient and unresectable tumors can be treated locally with trans-arterial chemoembolization, radioembolization, and systemic therapy.