Purpose: To assess the reliability of vacuum-assisted biopsy in diagnosing and managing atypical ductal hyperplasia and ductal carcinoma in situ of the breast.
Materials and method: Retrospective review of 2130 stereotactic large-core biopsies in 1638 patients over a 40 month period (January 2000 to May 2003) using the mammotome 11-gauge and a dedicated Fischer table. A total of 135 cases of atypical ductal hyperplasia and 322 cases of ductal carcinoma in situ were diagnosed. The average number of cores was 18 (5-64). Surgical resection was systematic for carcinomas and selective for atypical ductal hyperplasia. Correlation with surgical findings (n:356) or mammographic follow-up (n:98) is presented. The influence of various factors on the risk of underestimation was analyzed.
Results: Resection revealed an underestimation of 10/37 (27%) for atypical ductal hyperplasia. It was lower (9%) when the radiological lesion had completely disappeared. Underestimation of ductal carcinoma in situ was 12/319 (3.8%). It was higher for masses, high-grade lesions or with micro-infiltration, or in the case where the peripheral edge was affected. Of the 98 atypical ductal hyperplasia that were not surgically biopsied, 81 were monitored at 9-42 months (average: 29 months). Sixteen underwent repeat biopsy: two infiltrating lobular carcinomas were detected in the same area.
Conclusion: Underestimation of atypical ductal hyperplasia was high, justifying systematic surgical resection. Underestimation of ductal carcinoma in situ and its practical consequences are not significant with the extension of sentinel lymphadenectomy to the wide high-grade lesions or with micro-infiltration.