Atypical lobular hyperplasia and lobular carcinoma in situ at core needle biopsy of the breast: An incidental finding or are there characteristic imaging findings?

Background: Atypical lobular hyperplasia and classic-type lobular carcinoma in situ, collectively known as lobular neoplasia, are classically described as incidental findings found on breast core-needle biopsy without distinguishing imaging characteristics. OBJECTIVE: The purpose of this study was to investigate concordant imaging findings of lobular neoplasia identified at coreneedle biopsy after careful radiologic-pathologic correlation. METHODS: The pathology database was searched from October 1, 2006 to October 1, 2013 for breast biopsies yielding lobular neoplasia not associated with a coexistent malignancy or other high risk lesion in the biopsy specimen. RESULTS: Of the 482 biopsies performed containing lobular neoplasia, 65 cases had lobular neoplasia as the highest risk lesion at core-needle biopsy. Of the 65 total cases in which lobular neoplasia was the highest risk lesion, 18 (28%) cases had concordant imaging correlates. 13 of 18 (72%) cases presented as calcifications on mammography and 5 of 18 (28%) presented on magnetic resonance imaging as a focus (n = 2) or non-mass enhancement (n = 3). CONCLUSION: With careful radiologic-pathologic correlation, mammographically detected calcifications and foci or nonmass enhancement on magnetic resonance imaging can be considered concordant imaging findings of lobular neoplasia after breast core-needle biopsy.