Pulmonary metastases due to a giant-cell tumor of bone

Giant-cell tumors (GCT) of bone are commonly locally destructive and require total resection for cure (1). We describe a case of pulmonary metastases due to a GCT. A 19-yr-old woman presented with progressive knee pain and patella swelling after a bone cyst had been removed elsewhere 1 yr earlier. X-ray and computed tomography imaging (Fig. 1A) demonstrated near-total destruction of the patella with an intact cortical rim. To maintain the patellar function, marginal resection and reconstruction with bone cement were performed. Histopathological examination of the bone tissue established a diagnosis of a GCT of bone with large hypernucleated osteoclasts surrounded by stroma (Fig. 1B). The patient maintained good knee function, except for restricted flexion to 90°, allowing normal activities as a student. A chest x-ray 1 yr later revealed a centrally located radiopaque lesion in the right lung. On thoracic computed tomography, two round central lesions of 2.2 and 1.2 cm diameter were seen in both lungs (Fig. 1C). Both lesions were resected and found to be pulmonary metastases due to GCT. On follow-up 3 yr later, she has excellent knee function without signs of local recurrence or new pulmonary metastases. Pulmonary metastases represent a rare complication of GCT and should be resected (1, 2). In unresectable or recurrent cases, radiotherapy is recommended (3). Alternatively, denosumab, which blocks the cytokine receptor activator of nuclear factorB ligand (RANKL) may be beneficial (4) because GCT overexpress RANKL and its receptor (5). With the use of potent aminobisphosphonates and more recently denosumab, calcitonin has lost its role in the management of CGT. A recent study has demonstrated that it lacks efficacy (6).