Bone scintigraphy in the diagnosis of skeletal involvement and metastatic calcification in multiple myeloma.

The contribution of bone scintigraphy to the diagnosis of skeletal involvement in multiple myeloma was evaluated in a consecutive, unselected series of 25 previously untreated patients. Definite scintigraphic abnormalities were found in 11 patients (localized in 4, generalized in 7) (44%). In the majority of patients the clinical value of the information gained from scintigraphy was roughly equal to that found by radiography. However, 2 patients with normal and 2 with questionable bone scans had X-ray evidence of skeletal involvement, and the extent of bone destruction in 4 cases was seriously underestimated in the bone scans. Small osteolytic lesions were as a rule not detected by scintigraphy. On the other hand, in 8 patients the bone scan added information of involvement of ribs, pelvis and vertebrae, not clearly visualized by X-ray. In 2 patients, both with IgA myeloma, hypercalcemia and uremia, a massive extraskeletal uptake of the bone-seeking isotope was observed. Autopsy verified in one case the presence of a disseminated metastatic calcification.