Solitary metastasis to the skull as the first sign of hepatocellular carcinoma in a patient in long-term remission.

Background: Hepatocellular carcinoma (HCC) is a common malignant tumor with a 5-year survival rate of 10%, presenting with extrahepatic metastases in 15-17% of patients. HCC-bone metastases represent approximately one-quarter of all HCC metastases, most frequently in the spine, pelvis, ribs, or femur. HCC-skull metastases, however, make up 0.4-1.6% of all HCC- bone metastases. Furthermore, solitary HCC-skull metastasis without known active primary HCC is an unusual presentation warranting further review and consideration. Case Description: Here, the authors report a unique case of a solitary HCC-skull metastasis in a patient without known active cancer but in long-term remission for HCC. The patient is a 69-year-old male with past HCC who presented with a nontender skull mass. A computed tomography scan showed a heterogeneously enhancing mass centered in the high left parietal bone with intracranial extension. There was a noted mass effect on the left posterior frontoparietal region without worrisome midline shift. Pathology ultimately revealed the mass to be metastatic HCC. To aid in the understanding and clinical management of this rare presentation, we reviewed the literature regarding clinical presentation, radiological features, pathology, and outcome. Conclusion: Ultimately, early detection of the primary source of cancer is pivotal to successful treatment and prognosis, and skull lesions such as these must include HCC in the differential diagnosis.