Mammographic localization and biopsy of nonpalpable breast lesions. A 5-year study.

A malignancy rate of 24% was achieved as a result of needle localizations and biopsies of 548 nonpalpable mammographically detected breast lesions in 507 consecutive patients during a 5-year period. Malignancy was present in 74 (23.8%) of 311 irregular soft-tissue densities, in 40 (19.6%) of 204 cases with clustered microcalcifications, and in 33 cases (54.5%) when both features were present. Same-day admission and discharge were achieved in 491 patients and local anesthesia supplemented with intravenous sedation was used in 73 (74%) of the 98 patients (in 1989) by the end of the study period. Nonpalpable cancers were categorized pathologically as stage 0 in 25 patients (20.8%), stage I in 67 patients (55.8%), stage IIA in 24 patients (20.0%), and stage IIB in four patients (3.3%). The malignancy rate rose sharply from the fourth to the fifth decade.