Columnar cell change and columnar cell hyperplasia are two common, closely related, non-cancerous conditions that often develop together in the breast. They can only be seen after tissue from the breast is examined under the microscope by a pathologist. Columnar cell change and columnar cell hyperplasia are usually seen with another non-cancerous change called flat epithelial atypia.
Adult breast tissue is made up of small structures called glands which are organized into groups called lobules. Under certain conditions, these glands can produce milk, which is transported to the nipple by a series of small channels called ducts.
The inside of both glands and ducts is lined by specialized cells called epithelial cells which form a barrier called the epithelium. The tissue surrounding glands and ducts is called stroma and contains long, thin cells called fibroblasts.
In normal, healthy breast tissue, the ducts and glands are lined by a single layer of epithelial cells. Pathologists describe these cells as cuboidal because each cell is as tall as it is wide (like a square).
The diagnosis of columnar cell change (CCC) and columnar cell hyperplasia (CCH) can be made after a small sample of tissue is removed from the breast in a procedure called a core needle biopsy. The biopsy may be performed after calcifications were seen on mammography. Columnar cell change and columnar cell hyperplasia can also be discovered incidentally in tissue removed to diagnose or treat cancer or other non-cancerous condition in the same breast.
In both conditions, the glands are lined by columnar-shaped epithelial cells instead of the normal single layer of cuboidal epithelial cells. Columnar is a word pathologists use to describe cells that are taller than they are wide (like a rectangle).
The pathologist makes the distinction between the two conditions based on the number of columnar epithelial cells lining the glands. In columnar cell change (CCC), the glands are lined by one or two layers of cells. While in columnar cell hyperplasia (CCH), the glands are lined by more than two layers of cells. Hyperplasia is a word pathologists use to describe an increased number of cells compared to normal.
The columnar-shaped epithelial cells produce a fluid that is rich in calcium. Over time, some of the calcium in the fluid is left in the tissue where it creates calcifications. These calcifications are denser than normal breast tissue which allows them to be seen on mammography.