An update on the management of breast atypical ductal hyperplasia

Among lesions with uncertain malignant potential found at percutaneous breast biopsy, atypical ductal hyperplasia (ADH) carries both the highest risk of underestimation and the closest and most pathologist-dependent differential diagnosis with ductal carcinoma in situ (DCIS), matching the latter's features save for size only. ADH is therefore routinely surgically excised, but single-centre studies with limited sample size found low rates of upgrade to invasive cancer or DCIS. This suggests the possibility of surveillance over surgery in selected subgroups, considering the 2% threshold allowing for follow-up according to the Breast Imaging Reporting and Data System. A recent meta-analysis on 6458 lesions counters this approach, confirming that, surgically excised or managed with surveillance, ADH carries a 29% and 5% upgrade rate, respectively, invariably higher than 2% even in subgroups considering biopsy guidance and technique, needle calibre, apparent complete lesion removal. The high heterogeneity (I² = 80%) found in this meta-analysis reaffirmed the need to synthesise evidence from systematic reviews to achieve generalisable results, fit for guidelines development. Limited tissue sampling at percutaneous biopsy intrinsically hampers the prediction of ADH-associated malignancy. This prediction could be improved by using contrast-enhanced breast imaging and applying artificial intelligence on both pathology and imaging results, allowing for overtreatment reduction.