Introduction: Excisional biopsy is currently recommended for atypical ductal hyperplasia (ADH) diagnosed on core needle breast biopsy (CNB), due to risk of upstaging to invasive or in situ carcinoma (DCIS). The study goal was to identify patients who may potentially forego excisional biopsy if the risk of upstaging is low.
Methods: We conducted a retrospective review of patients diagnosed with ADH on CNB who underwent excisional biopsy at one institution (5/2000-5/2011). We evaluated the upstaging rate and clinicopathologic factors associated with increased upstaging risk.
Results: A total of 114 cases of ADH were diagnosed on CNB. The median patient age was 64 years. On mammography, a mass/density/area of distortion was present in 23 % of cases; calcifications were present in 77 %. Most biopsies (79 %) were performed stereotactically. Twenty lesions (18 %) were upstaged to infiltrating carcinoma (5 %) or DCIS (13 %). Residual ADH was present in 43 biopsies (38 %). On univariate analysis, significant variables associated with upstaging included age >50 years, a mass lesion on mammography, and shorter length of biopsy core (p < 0.05). No patient ≤50 years of age was upstaged. Three patients who were not upstaged (3 %) developed ipsilateral disease (2 DCIS and 1 infiltrating ductal carcinoma) at a median time of 37 months.
Conclusions: The rate of upstaging when ADH is diagnosed on CNB at our institution is 18 %, and routine excisional biopsy is currently recommended for all patients. However, patients <50 years old with focal atypia only and no residual calcifications postbiopsy may represent a low-risk group who could potentially avoid excisional biopsy.