Unusual extrahepatic metastatic site of hepatocellular carcinoma with post-therapy disseminating metastases presenting as a primary soft tissue sarcoma: case report.

INTRODUCTION AND IMPORTANCE

Hepatocellular carcinoma (HCC) is a highly malignant primary hepatic tumor. However, extrahepatic metastatic sites of HCC with post-therapy dissemination of metastases mimicking primary soft tissue sarcomas with rib metastases are extremely rare.

CASE PRESENTATION

The authors report a unique case of hepatitis B virus (HBV)-positive HCC with bilateral lung involvement and widespread right-flank soft tissue and rib metastases. The pathological diagnosis after surgical resection confirmed extrahepatic HCC metastasis. Subsequently, adjuvant-targeted and immune-checkpoint inhibitor therapies were still initiated.

CLINICAL DISCUSSION

Extrahepatic HCC metastasis, which initially presents at distant sites, is uncommon. HCC commonly metastasizes to the lungs, bones, lymph nodes, kidneys, adrenal glands, and peritoneum/omentum. HCC with aggressive post-scheduled adjuvant therapy to the lungs and hypochondriac soft tissue with rib metastasis is very rare and has a poor prognosis.

CONCLUSION

Although most patients with HCC have disseminated extrahepatic metastases, primary HCC should still be treated. Thus, a review of the history and imaging, histopathology, and immunohistochemical findings is crucial for the definite and differential diagnosis of this tumor.