Upgrade Rate of Atypical Ductal Hyperplasia: Ten Years Experience and Predictive Factors

Background: Atypical ductal hyperplasia (ADH) is a benign epithelial proliferative lesion with histologic features resembling those seen in low grade ductal carcinoma in situ (DCIS). Surgical excision of the biopsy site is the standard management approach. The objective of this study was to determine the upgrade rate from ADH on stereotactic breast biopsies to DCIS or invasive carcinoma (IC) in our institution. We also sought to identify clinical, pathologic and radiologic predictive factors associated with risk of upgrade.

Materials And Methods: Clinical charts, mammograms and pathology reports were reviewed for all women with a stereotactic breast biopsy showing ADH and subsequent surgery at our institution between 2008 and 2018. When available, mammograms were re-reviewed by a radiologist for this study.

Results: 295 biopsies were analyzed in 290 patients. Mean age was 56 y old. Upgrade rate was 10.5% of which 7.5% were DCIS and 3.1% IC. Mammograms were reviewed by a radiologist in 161 patients from 2013 to 2018. In this subset of patients, the rate of upgrade was 8.7% (4.35% DCIS and 4.35% IC). A statistically significant difference he largest size of the microcalcification clusters on mammogram was observed between the upgraded and the non-upgraded subgroups (14.2 mm versus 8.9 mm, P = 0.03) CONCLUSIONS: The evaluation of the largest size of microcalcification clusters on mammogram as a cut-off feature could be considered to choose between an observational versus a surgical approach. This large series provides contemporary data to assist informed decision making regarding the treatment of our patients.