Hyperplasia

Hyperplasia (also known as epithelial hyperplasia or proliferative breast disease) is an overgrowth of the cells that line the ducts or the lobules. Based on how the cells look under the microscope, the hyperplasia is called either ductal hyperplasia (also called duct epithelial hyperplasia) or lobular hyperplasia.

Based on the pattern of the cells, hyperplasia may be called usual or atypical. In usual hyperplasia, the pattern of cells is very close to normal. Atypical hyperplasia (or hyperplasia with atypia) is a term used when the cells are more distorted in their individual appearance and in how they are arranged..

Hyperplasia is usually diagnosed with a core needle biopsy or surgical biopsy. These different types affect breast cancer risk differently:

• Mild hyperplasia of the usual type: This does not increase the risk for breast cancer
• Moderate or florid hyperplasia of the usual type (without atypia), also known as usual hyperplasia: The risk of breast cancer is about 1½ to 2 times that of a woman with no breast abnormalities.
• Atypical hyperplasia (either atypical ductal hyperplasia [ADH] or atypical lobular hyperplasia [ALH]): The risk of breast cancer is about 3½ to 5 times higher than that of a woman with no breast abnormalities.

A diagnosis of hyperplasia, especially atypical hyperplasia, usually means you will need to see your doctor more often. This may mean more frequent breast exams and a special effort to get yearly mammograms, because some types of hyperplasia are linked to a higher risk of breast cancer in the future. Ask your doctor if your risk is high enough that you need breast MRI scans along with your screening mammograms.