Large-needle core biopsy: nonmalignant breast abnormalities evaluated with surgical excision or repeat core biopsy.

Abstract
PURPOSE: To classify lesions initially considered nonmalignant at large-needle core biopsy that were subsequently surgically excised or sampled at repeat biopsy. MATERIALS AND METHODS: From August 1, 1991, to December 31, 1996, 1,032 breast abnormalities (214 malignant and 818 nonmalignant lesions) were sampled at large-needle core biopsy. Of the nonmalignant lesions, 112 (14%) abnormalities were studied. Twenty-four abnormalities were subsequently excised because of discordant imaging and pathologic findings; 41 may have been missed at biopsy (25 were surgically excised, and 16 were sampled at repeat biopsy); 40 were surgically excised as recommended by the pathologist; and seven were excised for other indications. RESULTS: None of 24 abnormalities excised because of discordant findings was malignant. Among the 41 possibly missed lesions, infiltrating ductal carcinoma was found in one lesion that was removed surgically and in one sampled at repeat biopsy. Among the 40 lesions recommended for excision by the pathologist, 16 malignancies were found (ductal carcinoma in situ, 11; infiltrating ductal carcinoma, three; phyllodes tumor, two). None of the remaining seven lesions was malignant. CONCLUSION: Correlation of the technical quality of the biopsy, imaging features, and pathologic findings resulted in 96 surgical excisions and 16 repeat biopsies of lesions initially considered nonmalignant. Eighteen additional malignancies were identified.