Multicentric giant-cell tumor of bone.

The presence of more than one distinct giant-cell tumor in the same patient is rare; seven cases have been reported in the literature. The present series involves eleven patients with thirty-five individual tumors. Multifocal giant-cell tumors may pose a diagnostic problem. It is difficult to distinguish a multicentric giant-cell tumor from a primary giant-cell tumor with metastatic spread. This problem is magnified when the second lesion is not noted at the onset or is metaphyseal in location. Moreover, these lesions present a therapeutic challenge to the surgeon. Multiple lesions tend to exhibit the same aggressive clinical behavior as a solitary giant-cell tumor. A high recurrence rate after curettage indicates that aggressive surgical management is necessary.