Upstaging of atypical ductal hyperplasia after vacuum-assisted 11-gauge stereotactic core needle biopsy

Background: Nonpalpable mammographic abnormalities are frequently evaluated by means of a stereotactic core needle biopsy. This technique is a very sensitive indicator of invasive cancer, but is less reliable to discriminate between ductal carcinoma in situ and atypical ductal hyperplasia (ADH). The objective of this study was to determine the correlation of the 11-gauge vacuum-assisted core needle biopsy to open biopsy when a diagnosis of ADH is obtained. Hypothesis: The use of 11-gauge vacuum-assisted stereotactic core needle biopsy does not conclusively diagnose ADH. Design: Retrospective analysis. Setting: University-affiliated teaching hospital. Patients: Mammographic findings were evaluated with an 11-gauge vacuum-assisted stereotactic core biopsy in 1750 patients. Seventy-seven patients were diagnosed as having ADH; of these, 65 underwent excisional biopsy. Main Outcome Measures: Pathological upstaging rate. Results: Of the 65 patients who underwent excisional breast biopsy, 11 (17%) had their condition upstaged to a breast cancer diagnosis. These patients had presented at a later age than those who retained a benign diagnosis after excisional biopsy. The number of cores taken did not correlate with diagnostic accuracy. Conclusions: Of the 65 patients who underwent open biopsy for ADH in this series, only 83% had an accurate diagnosis. A diagnosis of ADH by stereotactic core needle biopsy should be followed by an open excisional biopsy.