Scintigraphic features of primary sacral tumors.

The bone scan features of different types of sacral tumors in 16 patients were assessed. Four out of five patients with chordoma, the most common sacral tumor, demonstrated either reduced uptake or normal distribution of isotope at the site of this midline tumor. Plasmacytoma, which is not usually central, also caused reduced uptake on the bone scan. Ewing's sarcoma gave no consistent pattern. All other tumors caused increased uptake except for one unusual case of osteogenic sarcoma. Bone scintigraphy can be very useful in the assessment of sacral tumors. A midline sacral tumor that is cold on the bone scan is very likely to be a chordoma.