A 58-year-old man visited an orthopedic clinic complaining of pain in his right lower back and numbness in his lower limbs for one month. Imaging tests revealed a tumorous lesion from the left side of the second lumbar vertebra to the paraspinal muscles. CT-guided biopsy of the tumor was performed, and immunostaining results diagnosed hepatocellular carcinoma (HCC). Although the liver showed signs of chronic liver damage, no primary tumor was found within the liver or in other organs. Blood tests showed negative hepatitis virus markers for both HBV and HCV. The tumor markers AFP, AFP-L3, and DCP were high. Because he developed spinal cord compression syndrome due to a lumbar tumor, radiation therapy and denosumab administration were performed. Subsequently, systemic therapy with durvalumab plus tremelimumab was started. In the year following the start of treatment, the tumor has shrunk, and no new lesions have been observed. Tumor markers have also decreased. We have experienced a case of HCC in the lumbar spine without a primary tumor in the liver. This is a very rare case, and the combination therapy with durvalumab and tremelimumab resulted in a complete response, which we consider to be a valuable case.

Hepatocellular carcinoma (HCC) is a primary liver tumor generally diagnosed based on radiographic findings. Metastatic disease is typically associated with increased tumor diameter, multifocality, and vascular invasion. We report a case of a patient who presented with extrahepatic HCC metastasis to a portocaval lymph node with occult hepatic primary on computed tomography (CT). We review the literature for cases of extrahepatic HCC presentation without known hepatic lesions and discuss strategies to differentiate between metastatic and ectopic HCC.

A 67-year-old male with remotely treated hepatis C was referred for evaluation of an enlarging portocaval, mixed cystic-solid mass. Serial CT evaluations demonstrated steatosis, but no cirrhosis or liver lesions. Endoscopic ultrasound demonstrated a normal-appearing pancreas, biliary tree, and liver. Fine needle aspiration yielded atypical cells. The differential diagnosis included duodenal or pancreatic cyst, lymphoproliferative cyst, stromal or mesenchymal lesions, nodal involvement from gastrointestinal or hematologic malignancy, or duodenal gastro-intestinal stromal tumor. After review by a multidisciplinary tumor board, the patient underwent open surgical resection of a 5.2 cm × 5.5 cm retroperitoneal mass with pathology consistent with moderately-differentiated HCC. Magnetic resonance imaging (MRI) subsequently demonstrated a 1.2 cm segment VIII hepatic lesion with late arterial enhancement, fatty sparing, and intrinsic T1 hyperintensity. Alpha fetoprotein was 23.3 ng/mL. The patient was diagnosed with HCC with portocaval nodal involvement. Review: We surveyed the literature for HCC presenting as extrahepatic masses without history of concurrent or prior intrahepatic HCC. We identified 18 cases of extrahepatic HCC ultimately found to represent metastatic lesions, and 30 cases of extrahepatic HCC found to be primary, ectopic HCC.

Hepatocellular carcinoma can seldomly present with extrahepatic metastasis in the setting of occult primary. In patients with risk factors for HCC and lesions suspicious for metastatic disease, MRI may be integral to identifying small hepatic lesions and differentiating from ectopic HCC. Tumor markers may also have utility in establishing the diagnosis.

The occurrence of hepatocellular carcinoma (HCC) is closely associated with viral hepatitis or alcoholic hepatitis. Although active surveillance is ongoing in Korea, advanced or metastatic HCC is found at initial presentation in many patients. Metastatic HCC presents with a hypervascular intrahepatic tumor and extrahepatic lesions such as lung or lymph node metastases. Cases of HCC presenting as carcinoma of unknown primary have been rarely reported. The authors experienced a case of metastatic HCC in a patient who presented with a metastatic bone lesion but no primary intrahepatic tumor. This case suggests that HCC should be considered as a differential diagnosis when evaluating the primary origin of metastatic carcinoma.

Hepatocellular carcinoma is the most common primary tumor of the liver. Spreading outside the liver usually takes place in advanced stages of the disease, and bone is the third most common site of metastases. We present a case of hepatocellular carcinoma in which the first clinical manifestation was a single metastasis to the carpal bones. The interest of this case lies in the way this hepatocellular carcinoma manifested as well as in the unusual site of the metastasis.