Objective: Our goals were to determine the frequency and upgrade rate for atypical ductal hyperplasia (ADH) diagnosed with stereotactic 9-gauge vacuum-assisted breast biopsy and to compare the frequencies and upgrade rates of ADH between 9- and 11-gauge vacuum-assisted breast biopsy.
Materials and methods: We retrospectively reviewed the pathology results of 991 consecutive 9- or 11-gauge stereotactic vacuum-assisted breast biopsy procedures from February 2001 through June 2006 and identified lesions diagnosed as ADH. The final diagnosis after surgical excision was determined from medical records. The frequencies and upgrade rates to carcinoma were calculated for all ADH lesions and compared between 9- and 11-gauge procedures. The number of core samples was recorded and compared.
Results: One hundred forty-one of 991 (14.2%) lesions yielded a diagnosis of ADH at 9- or 11-gauge stereotactic vacuum-assisted breast biopsy. Upgrade to ductal carcinoma in situ or invasive carcinoma occurred in 26 of 123 (21.1%) patients. The frequency of ADH was 83 of 600 (13.8%) lesions for 9-gauge and 58 of 391 (14.8%) lesions for 11-gauge vacuum-assisted breast biopsy. The 9-gauge upgrade rate was 16 of 74 (21.6%) lesions compared with 10 of 49 (20.4%) lesions for 11-gauge vacuum-assisted breast biopsy. There was no significant difference between the number of core samples obtained with each device (p=0.40). Neither the frequency of ADH (p=0.66) nor the upgrade rates (p=0.87) were significantly different between 9- and 11-gauge vacuum-assisted breast biopsy.
Conclusion: Compared with an 11-gauge vacuum-assisted breast biopsy device, the use of a larger 9-gauge vacuum-assisted breast biopsy needle does not decrease the upgrade rate of ADH. Our frequency of ADH at vacuum-assisted breast biopsy is higher than any previously reported and may reflect regional differences in the incidence of breast cancer or practice patterns of the pathologist.