The morphologic spectrum of lobular carcinoma in situ (LCIS) observations on clinical significance, management implications and diagnostic pitfalls of classic, florid and pleomorphic LCIS

Update on lobular lesions of the breast

“…86,87 Evidence shows that FLCIS and PCLIS are more aggressive variants and are usually completely excised to negative margins, similar to DCIS. 16,[27][28][29][30]32,37 However, unlike DCIS, appropriate margin clearance, as well as the role of radiation therapy and chemoprevention in non-CLCIS, is unclear. Currently, standard treatment for ILC is similar to IBC-NST at the same clinical stage and receptor profile.…”

“…Briefly, regardless of whether patients with ALH or LCIS undergo excision, these patients are usually offered endocrine therapy for chemoprevention, which reduces their risk of subsequent invasive carcinoma and DCIS 86,87 . Evidence shows that FLCIS and PCLIS are more aggressive variants and are usually completely excised to negative margins, similar to DCIS 16,27–30,32,37 . However, unlike DCIS, appropriate margin clearance, as well as the role of radiation therapy and chemoprevention in non‐CLCIS, is unclear.…”

“…8,42,44 When examining in-situ lesions, interpretation of the E-cadherin staining pattern should always be correlated with the morphology, given that residual benign ductal epithelium and intermingled myoepithelial cells display membranous E-cadherin expression, which should not be mistaken for retained expression in the neoplastic cells. 16,42 In addition, myoepithelial cells may show decreased E-cadherin staining compared to the benign ductal epithelium, which could be misinterpreted as LN.…”

“…In LCIS the cells adjacent to the necrosis are round to oval and appear discohesive, whereas in DCIS the cells are more cohesive and the apical membrane adjacent to the necrotic debris has a defined linear appearance (Figure 2E,F). 16 …”

“…In LCIS the cells adjacent to the necrosis are round to oval and appear discohesive, whereas in DCIS the cells are more cohesive Update on lobular lesions of the breast 37 and the apical membrane adjacent to the necrotic debris has a defined linear appearance (Figure 2E, F). 16 ALH and CLCIS are more commonly diagnosed in premenopausal women. These lesions are usually clinically and radiologically occult and considered incidental findings.…”