Scintigraphic features of giant cell tumor.

The scintigraphic appearance of giant cell tumor of bone in six patients is presented. Patients were studied by means of Tc-99m MDP bone scanning. On early blood pool and delayed imaging, markedly increased activity was noted, characteristically displaying a "ring" pattern that is readily discernible from patterns seen in bone cysts and nonosteogenic fibroma. The extent of the lesion, as judged by scintigraphic techniques, was roughly equal to estimates of extent by other radiographic modalities. Only one example of a different lesion mimicking giant cell tumor was encountered in over 100 cases of a variety of primary bone neoplasms reviewed. We conclude that giant cell tumor has a characteristic scintigraphic appearance.