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[Value of stereotactic breast core biopsy in patients with atypical ductal hyperplasia].

PURPOSE
Based on a dual center retrospective study, the risks of under-diagnosing clusters of microcalcifications on core biopsies are analyzed. Imaging and histopathological factors affecting this risk are explored.


MATERIALS AND METHODS
A total of 1,400 lesions (ACR BI-RADS 2-5) were reviewed and analyzed for size, degree of excision (%), and histology result. A total of 381 patients underwent surgery. Inter-center review of some histological slides was also performed.


RESULTS
The rate of under-diagnosis was 5.9% for ductal carcinoma in-situ (DCIS) and 12.5% for atypical ductal hyperplasia (ADH). Most cases of under-diagnosis involved clusters larger than 20 mm in diameter where the percentage of excision decreased from 98% (clusters<10 mm) to 9%. Review of histological slides showed inter-observer variability that decreased in relation to experience. ADH was never under-diagnosed when 3 or less foci were present. The risk of under-diagnosis for DCIS increased when the number of biopsies containing DCIS was superior to 50% and if the grade was high.


CONCLUSION
The presence of ADH on biopsy specimens requires surgical biopsy, but optimal core biopsies with cluster removal and histological analysis by an experienced observer allows identification of low risk patients that could undergo close follow-up.