Primary Combined Hepatocellular-Cholangiocarcinoma: A Case Report of an Under-Diagnosed Primary Liver Cancer

Background: Combined hepatocellular-cholangiocarcinoma (CHC) is a rare and aggressive primary tumor of the liver. Histologically, it comprises components of both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) but is associated with a worse prognosis. International guidelines regarding its management are scarce, with surgical management (major hepatectomy) being the treatment of choice. Case presentation: We present a 73-year-old male with a past medical history of alcohol dependance with a two-week history of the right upper quadrant (RUQ) abdominal pain that was sharp in nature. Abdominal examination showed tenderness in the RUQ, with a negative Murphy sign, and no hepatosplenomegaly was appreciated. An abdominal ultrasound (US) was done, which showed an enlarged liver of 17.7 cm with two hypoechoic lesions within the right hepatic lobe. The patient then underwent a CT abdomen with intravenous (IV) contrast that did not demonstrate any liver lesions. Due to equivocal findings on the US and CT abdomen, the patient underwent an MRI of the abdomen with and without contrast, which showed a conglomerated 6.4 x 8-cm mass in the left lobe of the liver, possibly suggesting a hepatoma or neoplastic mass, with mild dilatation of the biliary ducts in the left lower lobe, and normal common hepatic and common bile ducts. The patient was deemed a poor surgical candidate and underwent nuclear arterial mapping followed by yttrium-90 radioembolization of the left hepatic artery. On follow up he underwent an MRI for restaging, and it showed increased right hepatic lobe burden as well as venous thrombosis of the portal vein extending to the superior mesenteric vein. Due to the rapidly worsening status, the patient was not considered a candidate for further treatment and was transferred to hospice. Conclusion: CHC is a rare primary liver tumor, and preoperative clinical diagnosis is extremely difficult, making it an often underdiagnosed entity. Histology and immunohistopathology are the only ways for a definitive diagnosis. Surgical hepatectomy with hilar lymph node resection is the only curative treatment; however, other treatment options such as transarterial embolization, transarterial radioembolization, and/or systemic chemotherapy should be considered in inoperable patients as described in our case.