The significance of atypical lobular hyperplasia at percutaneous breast biopsy.

Atypical lobular hyperplasia (ALH) is occasionally found in specimens obtained by percutaneous stereotactic vacuum-assisted breast biopsy for microcalcifications. Since malignancy is often found at surgical excision when atypical ductal hyperplasia is found at percutaneous biopsy, we reviewed our pathologic findings from surgery for ALH at percutaneous biopsy. This was a retrospective review of all percutaneous breast biopsy specimens for mammographic microcalcifications obtained from a single institution over a 30-month period. The pathologic findings from percutaneous biopsy were correlated with the radiologic appearance and the pathology from surgical excision. ALH was found in 13 of 766 (1.7%) stereotactic vacuum-assisted core needle biopsies performed for mammographic microcalcifications. Subsequent surgery in six patients revealed ductal carcinoma in situ (DCIS) in two patients and one case of invasive ductal carcinoma. Surgical excision is indicated for areas with ALH discovered by percutaneous biopsy for mammographic microcalcifications.