Study Design.A case report.Objective.To report a case of the lumbar giant cell tumor (GCT) utilizing a new clinical treatment modality (denosumab therapy), which showed a massive tumor reduction combined with the L4 spondylectomy.Summary of Background Data.There are some controversies about spinal GCT treatments. Denosumab has provided good clinical results in terms of tumor shrinkage, and local control in a short-time follow-up clinical study phase 2, although for spinal lesions, it has not been described. Nonetheless, “en bloc” spondylectomy has been accepted as being the best treatments modalities in terms of oncological control.Methods.A case study with follow-up examination and series radiological assessments 6 months after therapy started, followed by a complex spine surgery.Results.The denosumab therapy showed on the lumbar computed tomography scans follow-up 6 months later, a marked tumor regression around 90% associated to vertebral body calcification, facilitating a successful L4 spondylectomy with an anterior and posterior reconstruction. The patient recovered without neurological deficits.Conclusion.A new therapeutic modality for spinal GCT is available and showing striking clinical results; however, it is necessary for well-designed studies to answer the real role of denosumab therapy avoiding or facilitating complex spine surgeries as spondylectomies for spinal GCT.Level of Evidence: 5