Ectopic Hepatocellular Carcinoma Arising in the Left Triangular Ligament of the Liver

Hepatocellular carcinoma (HCC) rarely originates in extrahepatic liver tissue. Laparoscopic resection is widely used to treat HCC. This report presents a case of a patient with ectopic HCC arising in the left triangular ligament of the liver that was successfully treated by laparoscopic resection. A 59-year-old female presented with an elevated serum alpha-fetoprotein (AFP) level (2,508 ng/ml). Dynamic computed tomography demonstrated a tumor measuring 20 mm in diameter below the left diaphragm just adjacent to the spleen. The tumor showed contrast enhancement in the hepatic arterial phase and became less dense than the liver parenchyma in the portal phase. The patient was diagnosed with ectopic HCC arising in the left diaphragm and laparoscopic surgery was performed. The tumor was located in the left triangular ligament of the liver and had a stalk between the tumor and the liver. The tumor was resected, and the final diagnosis was moderately differentiated ectopic HCC arising in the left triangular ligament of the liver. The patient had an uneventful postoperative recovery and has experienced no recurrence over 18 months after the operation.