Purpose: To assess the reliability of percutaneous breast biopsies in diagnosing and managing non malignant papillary lesions and determine if subsequent excision must be systematic. MATERIALS AND METHODS. Retrospective review of 2233 breast biopsies over a 43 months period (September 2001 to March 2005): sonographically guided core biopsies (n = 836), ultrasound (n = 346) or stereotactic (n:1051) guided vacuum biopsies. 86 non malignant papillary tumors were diagnosed (core biopsy:28, US:38 and stereotactic guided vacuum biopsy:20). A larger sample was systematic after core biopsy: lumpectomy (n = 19) or vacuum biopsy (n = 9). Surgical excision followed vacuum biopsy (n = 18) in case of atypia or sampling excision. Alternatively, yearly follow-up was advised (n = 40). Correlation with surgical findings (n = 37) or mammographic follow-up (n = 49) is presented. The influence of various factors on the risk of underestimation was analysed.
Results: Surgical resection revealed an underestimation of 5/37 (13.5%): 4/19 with core- and 1/18 with vacuum-assisted biopsy corresponding to 4 low grade ductal carcinoma in situ and a microinvasive ductal carcinoma in situ. It was higher for core biopsies and related to age and size: higher when women<50 years and when radiological image>1 cm. The influence of the other factors was not significant. Of the 9 non operated papillomas after core biopsy, vacuum biopsy revealed an additional underestimation (low-grade ductal carcinoma in situ). Of the 49 papillary lesions that were not surgically biopsied, 40 were monitored at 2-42 months (average: 19 months). No carcinoma was detected during this follow-up.
Conclusion: Percutaneous biopsy is an accurate technique in managing papillary tumors. A larger histologic specimen is necessary after core biopsy. Vacuum biopsy is an attractive alternative to surgery for smaller papillomas (<1 cm), but in spite of nonsignificant results we advise subsequent excision in case of multiple papillomas, atypia or residual tumor.