Flat epithelial atypia (FEA) is a non-cancerous condition that develops in the breast. This change can only be seen after tissue from the breast is examined under the microscope by a pathologist.
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).
Some cases of FEA may progress to cancer, but the risk of progression is very low. Studies have shown that women with flat epithelial atypia have a 1.5 times greater risk of developing breast cancer when compared to women without FEA.
The diagnosis of FEA 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. FEA can also be discovered incidentally in tissue removed to diagnose or treat cancer or other non-cancerous condition in the same breast.
In FEA the glands are lined by one or more layers of cuboidal or columnar epithelial cells that look abnormal in shape, size or colour when compared to normal, healthy epithelial cells. Pathologists use the word atypia to describe these abnormal cells.
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.
FEA is often seen together with other non-cancerous changes including:
FEA may also be seen in the breast tissue surrounding a pre-cancerous condition or cancer. Some of the more commonly associated conditions include: