Lobular carcinoma in situ at percutaneous breast biopsy: surgical biopsy findings.

OBJECTIVE: The purpose of this study was to review surgical histologic findings in women with lobular carcinoma in situ (LCIS) at percutaneous breast biopsy. MATERIALS AND METHODS: Retrospective review was performed of 1315 consecutive lesions that underwent percutaneous breast biopsy. Percutaneous biopsy yielded LCIS in 16 (1.2%) lesions. Subsequent surgical biopsy was performed in 14 lesions in 13 women. Histologic findings were reviewed. RESULTS: In five of the 14 lesions, percutaneous biopsy yielded LCIS and a high-risk lesion (radial scar in three and atypical ductal hyperplasia in two); in one (20%) of these five lesions, surgery revealed ductal carcinoma in situ (DCIS). In four of the 14 lesions, the LCIS in the percutaneous biopsy had features that overlapped with those of DCIS; in two (50%) of these four lesions, surgery revealed DCIS (n = 1) or infiltrating lobular carcinoma (n = 1). In the remaining five of the 14 lesions, surgery revealed no DCIS or infiltrating carcinoma. Five (38%) of 13 women with LCIS lesions had synchronous or metachronous infiltrating carcinoma (three ductal, one lobular, one mixed) in the ipsilateral (n = 1) or contralateral (n = 4) breast. CONCLUSION: Surgical excision was warranted in lesions in which LCIS was found at percutaneous breast biopsy when the percutaneous biopsy histologic features overlapped with those of DCIS, when a high-risk lesion was present, or when there was imaging-histologic discordance. LCIS without these factors was not shown to require surgical excision in our small series, but a larger study is needed. Diagnosis of LCIS at percutaneous biopsy is a marker for women who are at increased risk of ductal or lobular carcinoma in either breast.