title: Pure flat epithelial atypia is uncommon in subsequent breast excisions for atypical epithelial proliferation.
abstract: The management of atypical intraductal lesions of the breast remains controversial. In the present study, the subsequent surgical excision results and follow-up data on 86 (3.65%) atypical intraductal lesions and 78 (3.31%) low-grade ductal carcinoma in situ (DCIS) from a cohort of 2358 needle biopsies were examined. There were 17 cases (0.72%) of pure flat epithelial atypia (FEA), 44 (1.87%) pure atypical ductal hyperplasia (ADH), three (0.13%) pure atypical lobular hyperplasia (ALH), 18 (0.76%) combined ADH + FEA, three (0.13%) combined ALH + FEA and one (0.04%) combined ALH + FEA + ADH. Subsequent surgical excisions were done in 53 cases and revealed the following incidences of malignancy: pure FEA (1/8); pure ADH (17/31); FEA + ADH (7/10); FEA + ALH (2/3); and FEA + ALH + ADH (0/1), with pure FEA showing significantly lower incidence of malignancy. In this cohort, there were 703 carcinomas including 155 DCIS with 78 cases (50.3%) being low-grade. FEA with ADH (and/or ALH) was present in 22 (28.2%) of these 78 cases of low-grade DCISs at surgical excisions. Pure FEA was not detected in any of the subsequently excised surgical materials of the atypical intraductal lesions nor the low-grade DCISs. Thus, pure FEA was very unusual in surgical specimens. When pure FEA is detected at needle biopsy, a wait and see approach can be adopted. However, when the FEA is associated with other concomitant atypical intraductal lesions, especially ADH, further excision should be contemplated.
authors.affiliation: Department of Pathology and Laboratory Medicine, Kurume University Medical Center, Kurume, Japan. rin@med.kurume-u.ac.jp
authors.forename: Rin
authors.initials: R
authors.lastname: Yamaguchi
authors.forename: Maki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Gary M
authors.initials: GM
authors.lastname: Tse
authors.forename: Miki
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Terasaki
authors.forename: Jun
authors.initials: J
authors.lastname: Akiba
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Naito
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Mizushima
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Yano
mesh_terms: D001706:Biopsy; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology* / Q000601:surgery; D004848:Epithelium / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D060787:Neoplasm Grading