Lobular Neoplasia

Lobular neoplasia (LN) is a term that describes atypical epithelial lesions originating in the terminal duct-lobular unit (TDLU) of the breast, including atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS). LN is both a risk factor and nonobligate precursor to invasive breast cancer. A diagnosis of LCIS is associated with a 7-to-10-fold increased risk of breast cancer compared with the general population. When classic LN is diagnosed on a core needle biopsy (CNB), the patient may proceed with either increased screening or excisional biopsy of the lesion. Physicians should counsel patients diagnosed with LN on the risk of developing invasive carcinoma and inform them of the current screening and chemoprevention recommendations to reduce risk.