Flat Epithelial Atypia: A Review of Current Concepts

ABSTRACT

Columnar cell change in breast epithelium is frequently encountered in biopsies performed for evaluation of radiographically detected microcalcifications. While columnar cell change by itself is typically of no clinical consequence, on occasion cytologic atypia may be present, a finding now termed “flat epithelial atypia (FEA)”. Morphologic, immunophenotypic, and genetic associations between FEA and low grade in situ and invasive breast carcinomas provide compelling evidence that FEA represents a precursor lesion in the spectrum of low grade breast neoplasia. Despite this information, the ultimate clinical impact of FEA and, thus, the best management strategy for it remains unknown. Herein, current concepts regarding FEA are reviewed, including pathologic definition, evidence supporting its role as a neoplastic precursor, and suggested management strategies.