Multiple Pulmonary Metastases of Giant Cell Tumor of Bone with expression of VEGFR-2 Successfully Treated by Denosumab and Apatinib: A Rare Case Report

Abstract

\n Background: Giant cell tumor of bone (GCTB) is a rare benign but locally aggressive bone tumor. It has a high tendency for local recurrence, which may increase the occurrence of lung metastasis. Currently, the treatment of pulmonary metastases of GCTB is controversial. Denosumab is the preferred regimen for unresectable metastatic lesions, but there are no alternative treatment options when denosumab is resistant. So far, no case reports of metastatic GCTB treated with denosumab and apatinib have been published. Case presentation: This is a case report of a 26-year-old female who experienced right knee pain for over 6 months. Radiography and computed tomography revealed osteolytic bony destruction in the proximal right tibia. Using histological, radiological, and clinical techniques, a diagnosis of GCTB was achieved. Meanwhile, the immunohistochemical stain-identified the tumor cells were positive for vascular endothelial growth factor receptor 2 (VEGFR-2). After intralesional curettage of the primary tumor and wide resection of local recurrence surgeries, she developed recurrent hemoptysis. Chest computed tomography (CT) images showed multiple pulmonary nodules. She was administrated denosumab therapy but disease progression was confirmed after four months of treatment. She then received denosumab and apatinib therapy for 24 months, after a partial response was achieved.Conclusions: We depict a case of multiple pulmonary metastases of GCTB successfully controlled by denosumab and apatinib therapy. VEGFR-2 may be an effective therapeutic target for GCTB with pulmonary metastasis when denosumab is ineffective.