Flat epithelial atypia (DIN 1a, atypical columnar change): an underdiagnosed entity very frequently coexisting with lobular neoplasia

Abstract

Due to the striking association between LN and FEA in our material, one may speculate that these two lesions are biologically related and that FEA is an early but non-obligate precursor lesion similar to LN. Based on this assumption, regular clinical and mammographic follow-up of patients with FEA would be prudent.