Flat epithelial atypia (FEA) refers to a specific microscopic finding in breast tissue. It is characterized by unusual cellular changes within the breast ducts or lobules, identified by pathologists. While these cells appear abnormal, FEA itself is not breast cancer, but a distinct pattern of cellular appearance.
Understanding Flat Epithelial Atypia
Flat epithelial atypia is a classification for atypical cell changes occurring within the terminal duct lobular units of the breast. The cells involved are columnar in shape and line the ducts in one to several layers. These cells display low-grade cytologic atypia, with nuclei often round, small, uniform, and evenly spaced with fine chromatin. This appearance distinguishes FEA from normal breast cells.
FEA is not considered breast cancer. However, it is categorized as a “high-risk lesion” or a “lesion of uncertain malignant potential.” It is associated with a slightly increased lifetime risk of developing breast cancer. FEA can also be found alongside or in close proximity to areas of actual breast cancer, such as ductal carcinoma in situ (DCIS) or invasive carcinoma. Emerging evidence suggests that FEA might represent an early form of low-grade DCIS.
How Flat Epithelial Atypia is Diagnosed
Flat epithelial atypia is almost always an incidental microscopic finding, as patients typically do not experience symptoms. It is commonly discovered during a breast biopsy performed for other reasons, such as suspicious findings on routine breast imaging like microcalcifications on a mammogram or a mass on an ultrasound.
The definitive diagnosis of FEA is made by a pathologist who examines the tissue sample. The pathologist scrutinizes the cells for specific features, such as low-grade nuclear atypia and the “flat” growth pattern. This microscopic evaluation allows for differentiation of FEA from other benign alterations or more advanced atypical lesions like atypical ductal hyperplasia (ADH) or ductal carcinoma in situ (DCIS).
Next Steps After a Flat Epithelial Atypia Diagnosis
Following a diagnosis of flat epithelial atypia, the case is frequently reviewed by a multidisciplinary team of breast specialists. This team typically includes radiologists, breast surgeons, and pathologists, who assess all available clinical, imaging, and pathological information. This review helps determine the most appropriate course of action, taking into account the specifics of the FEA finding and the patient’s overall health profile.
Surgical excision, which involves removing a small area of tissue around the site where FEA was found, is a common recommendation. This is to ensure that no more significant lesions, such as ductal carcinoma in situ or invasive cancer, were missed or are co-existing. Studies have shown that a percentage of FEA diagnoses on needle biopsy can be “upgraded” to cancer upon surgical excision, with rates ranging from approximately 3.2% to 5% in some studies.
If the surgical excision confirms only FEA and no other high-risk or malignant lesions, ongoing surveillance is typically recommended. This may involve regular mammograms, potentially supplemented by other imaging techniques like ultrasound or MRI, and periodic clinical breast exams. Management decisions are individualized, considering the specific pathology, the appearance of the lesion on imaging, and the patient’s personal risk factors for breast cancer.