Answer:
Giant cell tumor of bone accounts for 5% of benign bone tumors but only 2% of these tumors occur in the hand. Most patients are between 20-55 years of age and women outnumber men 2:1. They usually arise early in the fourth decade of life and present most commonly in the metacarpals and phalanges but have also been seen in the distal radius and carpus. Patients present with pain and swelling in the affected area or following a pathologic fracture. Radiographic findings include a lytic lesion with an indistinct border. Cortical expansion, destruction, and soft tissue extension are commonly seen. Although these are considered benign tumors, they may behave locally in an aggressive fashion and even metastasize with eventual death. Histologically, the tumors consist of two populations: mononuclear stromal cell and a osteoclast-resembling giant cells. The histologic appearance does not correlate with the biological activity. These tumors can be multicentric and pulmonary metastases have been reported from histologically benign giant cell tumors in the hand. Therefore, these tumors should be treated as a low-grade malignancy. Patients should be staged with chest radiographs and bone scan to rule out pulmonary metastases and multicentric lesions. The treatment is wide excision with subsequent reconstruction. Lesions of the phalanges and metacarpals may require amputation. If the cortex has not been perforated and no soft tissue extension is present then curettage with cryosurgery may be considered. Curettage alone has shown a recurrence rate of up to 80%. Chemotherapy is not effective. Radiation therapy, however, has shown to be effective but carries an 8.7% risk of malignant transformation which is usually fatal.