Biopsy of occult breast lesions. Analysis of 1261 abnormalities.

From January 1, 1987, to December 31, 1988, roentgenographically guided biopsies of 1261 occult breast abnormalities were performed. There were 626 (49.6%) masses and 635 (50.4%) lesions with calcification as the dominant feature. Of the total, 237 (18.8%) were found to be malignant, including 85 cases of ductal carcinoma in situ. Biopsies performed for a mass yielded a 20.8% (130/626) incidence of cancer; and for calcification, 16.9% (107/635). The biopsy results were supported by the interpretations of four radiologists (J.E.M., P.C.S., and M.R.S.) who were practicing at Brigham and Women's Hospital in 22.2% of the total (280), whereas the remaining 981 lesions were discovered on mammograms that were performed and interpreted elsewhere and were referred to our hospital for surgical consultation. The biopsy results of the mammograms from other facilities yielded a positive predictive value of 16.7% (164/981) vs 26.1% (73/280) for the Brigham and Women's Hospital group. This statistically significant difference lends support to the value of a second opinion in patients with biopsy recommendations for occult breast lesions, especially when findings are inconclusive.