Translaminar Screw Fixation for Giant C1 Lateral Mass Metastasis From Hepatocellular Carcinoma

Metastatic spinal tumors at the craniovertebral junction (CVJ) are exceedingly rare, with limited reports of C1 lateral mass metastases from hepatocellular carcinoma (HCC). This report presents a case in which posterior fixation alone successfully achieved pain relief and improved stability in a patient with HCC metastasis involving extensive osteolysis of a C1 lateral mass and encasement of the vertebral artery. A 71-year-old male presented with a worsening right cervical pain. The patient had been prescribed nonsteroidal anti-inflammatory drugs and opioid analgesics, yet the pain remained unresolved. Computed tomography (CT) revealed a 5.5 cm osteolytic tumor at the C1 lateral mass with circumferential involvement of the vertebral artery. The patient was diagnosed with spinal metastasis from HCC, characterized by spinal instability (Spinal Instability Neoplastic Score (SINS), 11) and intractable pain (visual analog scale (VAS), 7.7). The patient was bedridden because of an inability to support head loads (performance status (PS), 4), and it was considered difficult to initiate ongoing chemotherapy. The patient was referred for surgical intervention to relieve the pain and improve stability. To address the pain and instability, occipitocervical (C2-C5) posterior fixation was performed without tumor resection. Due to extensive tumor invasion, pedicle screw placement at C2 was not feasible, and C2 translaminar screw fixation was selected instead. Postoperatively, the patient experienced significant pain relief and regained ambulatory ability. At one month postoperatively, fixation remained stable, with VAS improving to 0.8 and PS to 1. The patient was able to maintain pain relief and exhibited improved stability, allowing him to walk, and durvalumab/tremelimumab chemotherapy was initiated two months after surgery. The primary goals of managing metastatic tumors at the CVJ are pain relief, neurological function preservation, and spinal stability. In this case, posterior fixation alone achieved substantial pain alleviation and stability improvement without tumor resection. Notably, the use of C2 translaminar screws minimized the risks of spinal cord and vertebral artery injuries while ensuring effective stabilization. This is the first report to demonstrate the efficacy of posterior fixation alone for HCC metastases with complete destruction of the articular facet at C1. Posterior fixation alone can provide effective pain relief and restore stability in metastatic tumors with severe osteolysis of the C1 lateral mass. Careful selection of fixation techniques can minimize intraoperative complications while improving the patient's quality of life. This report contributes to surgical strategies for similar cases.