Mammography of women with suspicious breast lumps.

We analyzed 342 women who had suspicious breast lumps to determine if preoperative mammography could improve the malignancy yield of biopsy procedures. The number of women with cancer of the breast and false-negative mammogram reports ranged from 11% to 25%, depending on how equivocal mammogram reports were interpreted. Therefore, women with clinically suspicious breast lumps should undergo biopsy regardless of mammographic findings. A significant difference in the mean (+/- SD) predictive value of a positive mammogram existed between women above and below the age of 50 years (80 +/- 8 vs 43 +/- 14) because of the age-specific relative prevalence of benign and malignant disease, and because mammography had difficulty distinguishing between benign and malignant lumps (specificity, 70). Preoperative mammography of women with suspicious breast lumps is indicated to screen for occult carcinoma, to prevent biopsy sampling errors, and to judge the adequacy of lumpectomy if the lesion is malignant.