False positive bone scan in bone tumors of the lower limb.

When examined using bone scanning agents, eight out of nine patients with lower limb malignancy, and neither of two affected in the upper limb showed a pathologic focus of isotope uptake in an area distal to the tumor. On pathologic examination the positive findings proved false. Such misleading results were found to be avoidable if a tumor-seeking agent instead of a bone scanning one is used.