Scintigraphy of benign exostoses and exostotic chondrosarcomas.

Technetium-99m diphosphonate scintigraphy of 11 benign exostoses and nine exostotic chondrosarcomas was correlated with pathologic macrosections of the resected tumors. Increased uptake in benign exostoses occurred in areas of enchondral ossification, and uptake in chondrosarcomas occurred in areas where ossification, osteoblastic activity, and hyperemia were found. Uptake was not related to amorphous cartilage calcification. Radiopharmaceutical uptake, therefore, correlated with areas of ossification visible radiographically, and large masses of nonossifying cartilage were not detected. Radionuclide bone imaging did not contribute to the preoperative anatomic evaluation of these tumors, and it did not always distinguish benign from malignant lesions.