Hyperplasia and atypical hyperplasia

What is hyperplasia?

The breasts are made up of lobules (milk-producing glands) and ducts (tubes that carry milk to the nipple), which are surrounded by fatty tissue and supportive tissue.

Sometimes normal cells within the breast grow bigger and increase in number. This is called hyperplasia. It can occur in the ducts (ductal hyperplasia) or the lobules (lobular hyperplasia).

Hyperplasia is benign (non-cancerous), and usually develops naturally as the breast ages and changes. It can affect women of any age. Hyperplasia doesn’t produce any symptoms or cause pain and is usually found by chance.

What is atypical hyperplasia?

Atypical hyperplasia is where the cells within the breast develop an unusual pattern and shape. Again it can occur in the ducts (atypical ductal hyperplasia) and the lobules (atypical lobular hyperplasia).

Atypical hyperplasia is also benign (non-cancerous) and doesn’t produce any symptoms or cause any pain.

However, as it’s possible that the abnormal cells in the ducts may spread to the surrounding tissue, having atypical hyperplasia has been shown to slightly increase the risk of developing breast cancer in the future.

Atypical lobular hyperplasia is a form of lobular neoplasia, another benign breast condition, For more information on this condition, visit our section on lobular neoplasia.

How are they diagnosed?

Both hyperplasia and atypical hyperplasia are usually found by chance at the breast clinic when the tissue from a biopsy or breast surgery is examined under the microscope in the laboratory.

Treatment and follow up

Hyperplasia

In most cases you won’t need any treatment or follow up if you have hyperplasia.

Atypical hyperplasia

A diagnosis of atypical hyperplasia will usually be made following a biopsy. Once this has been established, your specialist may want you to have an operation to ensure the atypical hyperplasia has been removed.

Your specialist is likely to want you to have follow-up appointments as well. This may include regular clinic visits and a mammogram every one to two years.

What this means for you

Hyperplasia

Having hyperplasia does not increase your risk of developing breast cancer. However, it’s still important to be breast aware and go back to your GP if you notice any changes in your breasts.

Atypical hyperplasia

If you have atypical hyperplasia, you may be worried or anxious that your risk of breast cancer is slightly increased.

Please remember that this doesn’t mean you’ll necessarily develop breast cancer in the future. However, it is important to go to your regular follow-up appointments and continue to be breast aware.

For more information on how to be breast aware, download or order our free publication, Your breast, your health – throughout your life.