Mild ductal atypia after large-core needle biopsy of the breast: Is surgical excision always necessary?

Background. The aim of the current study was to identify a select group of patients with mild atypia who do not need surgical excision after large-cor e needle biopsy (LCNB) of the breast. Methods. Nineteen (70 %) of 27 patients with ductal atypia found on LCNB ha d subsequent surgical excision. These 19 patients were retrospectively assi gned to 3 groups according to the severity of the atypia found which was co mpared with the final pathologic specimen after surgical biopsy. Results. Cancer was identified through surgical biopsy in 6 (32 %) of 19 pa tients. The severity of atypia seen on the LCNB specimen strongly correlate d with subsequent cancer identification (P <.01). Two (33 %) of 6 patients in group 2 (true atypical ductal hyperplasia [ADH]) and 4 (80 %) of 5 patie nts in group 3 (severe ADH, borderline ductal carcinoma in situ) had cancer after surgical biopsy. No cancer was found after surgical biopsy in 8 pati ents in group 1 (mild atypia, not meeting criteria for ADN). Conclusions. The results of this study suggest that surgical excision can b e avoided after LCNB of the breast in patients with only mildly atypical le sions that do not meet criteria for ADH. Patients with true ADH should cont inue to have surgical excision.