Solitary lesions on bone scan in genitourinary malignancy.

Solitary lesions on bone scans obtained as part of metastatic diagnostic studies for genitourinary malignancy require identification as to whether they represent nonneoplastic or neoplastic disease and, if neoplastic, whether metastatic genitourinary cancer or another primary is present. Such definition requires at least plain film tomograms of the area as well as computerized tomography (for inaccessible lesions) and/or biopsy of lesions still in doubt after tomography. Of the 9 patients in our study 4 had true positive scans for metastatic disease, 3 had false positive scans, 1 had a true positive scan for a second bone primary and 1 is indeterminate, since a negative biopsy of a positive area on a bone scan was followed rapidly by the appearance of other widespread metastases.