Metastatic Giant Cell Tumor of Bone

Giant cell tumors of bone are sometimes locally aggressive and may metastasize, although uncom- monly. We attempted to identify associations of clinical and histopathologic parameters with metastasis, the long- term outcome with metastases, and the best treatment. We identified distant metastases in 24 of 470 patients with giant cell tumors during a 20-year period. The median age of these 24 patients at presentation was 26 years (range, 16-76 years), and the male:female ratio was 1.6:1, with no predilection for primary site. Metastasis occurred at a mean of 2 years (range, 4 months-11 years) after initial diag- nosis. Sites for distant metastases were the lung (21 of 24 patients), scalp, calf muscle, and regional lymph nodes. The 24 patients had a mean followup of 3.5 years (range, 0-16 years). Thirteen of the 24 patients has local recur- rence before or at the time of metastasis. Two patients refused treatment, eight underwent metastasectomy, and 14 were inoperable (four had chemotherapy, 10 were treated symptomatically). We observed disease progression with hemoptysis in one of 14 patients. None of the patients died of their metastatic disease. None of the risk factors we studied was associated with metastasis in giant cell tumors. Although the overall outcome was favorable, metastasec- tomy is recommended where feasible. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.