Nonpalpable lesions detected with mammography: review of 512 consecutive cases.

The authors reviewed 512 consecutive cases in which biopsies were performed on nonpalpable lesions of the breast detected with mammography from 1970 to 1985. The positive predictive value (PPV) of different radiologic patterns was determined. Biopsy is advised in the presence of patterns such as parenchymal distortion, opacities with undefined borders, strongly suspect microcalcifications (rodlike or branching morphologic features, high spatial density), and stellate opacities, which yielded higher PPVs (0.11, 0.35, 0.56, and 0.75, respectively). The average detection rate of preclinical cancer was 0.7 per 1,000; wide variations were recorded during different periods in the study (0.2 per 1,000 and 1.3 per 1,000 in the first 4 years and the last 4 years of the study, respectively), for the different age groups considered (0.6 per 1,000 and 1.7 per 1,000 for the 30-39-year and over-59-year age groups, respectively), and for different reporting radiologists (0.5-1.9 per 1,000). The ratio of benign to malignant biopsy findings was 2.4:1 for the whole series, with wide variations encountered relative to the variables mentioned above.