[Flat epithelial atypia of the breast]

ABSTRACT

"Flat epithelial atypia" is the adopted term by the WHO working group on breast tumor referring to an early neoplastic breast lesion affecting the terminal duct-lobular units. Pathologists have described this lesion under a variety of names including columnar cell lesions and low-grade clinging carcinoma in situ. It is usually encountered on breast biopsies performed for mammographically-identified microcalcifications. Because of its relatively frequent association with carcinomas, its recognition in biopsy specimens is important. This review will focus on the histopathologic features, differential diagnosis, biologic potential, clinical significance and management of this lesion