Preoperative localization of clinically occult breast lesions: experience at a referral hospital.

The authors performed 601 preoperative needle localization procedures for occult breast abnormalities in 1987. Whereas most previous series have been based on mammograms obtained and interpreted at the reporting institutions, this study population includes a large number of patients (79%) examined and referred from other facilities. One hundred nine cancers were diagnosed in the 601 cases (18%). Biopsies performed for masses yielded a 23% (64 of 278) frequency of cancer and those for calcification, 14% (45 of 323). The benign to malignant ratio (4.5:1) in this mixed group of patients is higher than that cited in reports of other large series. An analysis of the factors that might influence these statistics is presented.