Biopsy of nonpalpable breast lesions.

One hundred-three needle-direct breast biopsies were performed in 99 patients. Nine cancers were detected. All of the patients but one had in situ tumor or stage I disease. After analysis, the mammograms were submitted to radiologists for restudy in a blinded fashion. On restudy, 50 percent of the malignancies were read as low suspicion or benign whereas the other 50 percent were read as malignant. Variation between interpretations was significant, with complete agreement among the radiologists in 16 percent of cases. We concluded that needle-directed biopsy for occult breast lesions is very effective in bringing patients with a more favorable prognosis to early surgery. The false-positive rate will be high and the interpretation of a given mammogram will vary, depending on the radiologist. Mammography for subtle lesions is sensitive but nonspecific; therefore, it is wise to biopsy all lesions that are even slightly suspicious, particularly in patients with a previous history of breast cancer or other risk factors.