Triad of columnar cell alteration, lobular carcinoma in situ, and tubular carcinoma of the breast.

Columnar cell alteration in the breast encompasses a spectrum of pathologic changes ranging from simple columnar cell change to more complex columnar cell hyperplasia with and without atypia to in situ carcinoma, often with a micropapillary architecture. For reasons that remain unclear, the columnar cell lesions are associated with tubular carcinomas and lobular carcinoma in situ. Therefore it is important to be familiar with the spectrum of changes and the associated lesions, especially in breast core biopsies for further management.