Scintigraphy of aneurysmal bone cysts.

Bone scintigrams of 25 aneurysmal bone cysts showed abnormal activity in every case. In 22 cases, the activity was correlated with the true pathologic extent of the lesions; only three exhibited a false-positive extended pattern of uptake beyond the true tumor margins. Sixteen scintigrams (64%) revealed increased uptake, chiefly around the periphery of the lesions, with less activity in their centers. This feature could not be explained simply by the cystic nature of the lesions, since aneurysmal bone cysts may contain considerable fibrous tissue septa containing trabeculae of reactive new bone. However, there was no correlation between any specific anatomic or histologic pattern and the intensity and pattern of abnormal scintigraphic activity.