Columnar Cell Lesions of the Breast

Abstract

Abstract: Columnar cell lesions (CCLs) of the breast are very common flat epithelial proliferations characterized by columnar epithelial cells lining the terminal duct-lobular unit. They are often associated with microcalcifications and have been observed with an increasing frequency in image-directed core needle biopsies of the breast. Flat epithelial atypia) are CCLs exhibiting cytologic atypia of the type seen in low-grade ductal carcinoma in situ; these lesions have been seen in association with ductal carcinoma in situ, lobular neoplasia, and invasive tubular carcinoma. Recently, flat epithelial atypia has been claimed to represent a potential nonobligate precursor or even an earliest recognizable form of low-grade ductal and lobular carcinoma in situ and some invasive carcinomas. There is no consensus on management of these lesions when they are diagnosed on percutaneous imaging-guided core needle biopsy. We present a case of CCL, discuss the morphologic classification, biologic significance, and management guidelines of these lesions.