Cryosurgical cranioplasty using autologous bone for metastatic skull lesion from hepatocellular carcinoma: illustrative case.

BACKGROUND: Skull metastases from hepatocellular carcinoma (HCC) are rare and may cause significant neurological deficits. Conventional cranioplasty using titanium mesh or polyetheretherketone can result in imaging artifacts and implant-related complications. Cryotherapy provides a potential means to sterilize tumor-infiltrated autologous bone for reuse in reconstruction. OBSERVATIONS: A man in his 50s with hepatitis B virus-associated HCC presented with cognitive and speech disturbances. Imaging revealed a 5-cm left temporo-parieto-occipital skull lesion with intracranial extension. The tumor-infiltrated bone flap was excised, treated with liquid nitrogen at -60°C to -80°C for 20 minutes, and reimplanted after tumor resection. Histopathology confirmed metastatic HCC involving the skull and brain. Three-month follow-up MRI and CT demonstrated no recurrence, excellent bone flap integration, and no imaging artifacts. The patient's neurological symptoms were resolved postoperatively. LESSONS: Cryosurgical cranioplasty using autologous bone offers a biologically compatible, imaging-friendly, and oncologically safe alternative to synthetic implants for metastatic skull lesions, enabling effective reconstruction and reliable postoperative surveillance. https://thejns.org/doi/10.3171/CASE25852.