Lobular Neoplasia Diagnosed at Core Biopsy Does Not Mandate Surgical Excision

Background: Lobular intraepithelial neoplasia (LIN) is associated with an increased risk of breast malignancy. The significance of LIN diagnosed at core needle biopsy (CNB) is unclear, although many groups recommend surgical excision to rule out lesions, which would require immediate, definitive therapy. Current management options include clinical/mammographic observation and surgical excision. The necessity of routine surgical excision remains controversial due to conflicting opinions on the biological behavior of lobular lesions, diagnostic confusion regarding histopathology, and uncertainty of their association with high-risk lesions. The purpose of this report was to review the published data regarding the incidence of high-risk lesions associated with LIN diagnosed at CNB to clarify the indications for surgical excision. Materials and methods: A PubMed search was performed to identify all published articles in English addressing management of LIN diagnosed at CNB. Results: The 19 studies that form the basis of this report included a total of 504 subjects. Although the studies differed greatly in their content and methods, they were analyzed as a group for the presence of criteria deemed by the authors to be the most important information to include in a study regarding this issue and thus a reasonably good indicator of the quality of the literature. All of the studies were retrospective, nearly half were nonconsecutive series, and no study reported clear inclusion criteria for surgical excision versus observation. Limitations of the reviewed studies included their retrospective nature, small number of subjects, inconsistent inclusion criteria, and selection bias regarding surgical excision. Conclusions: Based on the reviewed literature, it is difficult to reach a firm evidence-based conclusion regarding optimal management of LIN diagnosed at CNB. Associated high-risk lesions increase the risk of upgrade, but there are no mammographic predictors. The available retrospective literature suggests that some cases of LIN are associated with higher-risk lesions identified on surgical excision but does not support routine excision for all patients.