To determine the incidence of malignancy (invasive carcinoma or DCIS) in patients diagnosed with lobular neoplasia (B3) on core needle biopsy (CNB) of breast lesions by reviewing the published literature.Medline, Embase, OVID-database and reference lists were searched to identify and review all English-language articles addressing the management of LN diagnosed on CNB. Studies on mixed breast pathologies were excluded.Of 1229 LN diagnosed on CNB, 789 (64%) underwent surgical excision. 211 (27%) of excisions contained either DCIS or invasive disease. 280 of the excision specimens were classified as ALH, 241 as LCIS, 22 as pleomorphic LCIS and 246 unspecified LN on the original CNB. After surgical excision, 19% of the ALH cases, 32% of the LCIS cases and 41% of the PLCIS cases, contained malignancy. 29% of the unspecified LNs were upgraded to malignancy. The higher incidence of malignancy within excision specimens for LCIS and PLCIS compared to ALH was significant (P < 0.04, <0.003 respectively).There is a significant underestimation of malignancy in patients diagnosed with breast LN on CNB. 27% cases of CNB-diagnosed LN were found to contain malignancy following surgical excision. All patients diagnosed with LN on CNB should be considered for surgical excision biopsy.