Hyperplasia and atypical hyperplasia

Hyperplasia is a benign (not cancer) breast condition.

It does not usually cause any symptoms in the breast.

Hyperplasia happens when there’s an increase in the number of cells lining the ducts (tubes that carry milk to the nipple) or lobules (milk-producing glands) of the breast. 

When hyperplasia occurs in the ducts it’s called ductal hyperplasia. Ductal hyperplasia can be either "usual" or "atypical". Atypical means "not typical".

When hyperplasia occurs in the lobules it’s called atypical lobular hyperplasia.

Atypical hyperplasia (also called epithelial hyperplasia) happens when cells lining the ducts or lobules increase in number and develop an unusual pattern or shape.

Atypical hyperplasia is also benign (not cancer). However, having atypical hyperplasia has been shown to increase the risk of breast cancer in some people. 

Hyperplasia usually develops naturally as the breast changes with age. It’s more common in women over 35 but can affect women of any age.

Hyperplasia and atypical hyperplasia can also affect men, but this is very rare.

Hyperplasia and atypical hyperplasia do not usually cause any symptoms. Because of this, they’re usually found by chance when breast tissue that has been removed during a biopsy or breast surgery is examined under a microscope in the laboratory.

Usual ductal hyperplasia 

Usual ductal hyperplasia does not usually need any treatment or follow-up.

Atypical ductal or lobular hyperplasia 

If you have atypical hyperplasia, your doctor may want you to have more tissue removed to examine the area more thoroughly.

This tissue may be removed by a vacuum assisted excision biopsy or a surgical excision biopsy.

In both cases, the tissue removed will be sent to a laboratory to be examined under a microscope. This will confirm the diagnosis of atypical hyperplasia and check for any changes that could be breast cancer.

Vacuum assisted excision biopsy

After an injection of local anaesthetic (where the area is numbed), a small cut is made in the skin. A special needle connected to a vacuum device is placed through this cut. Using a mammogram or ultrasound as a guide, breast tissue is sucked through the needle by the vacuum into a collecting chamber.

The biopsy device is used until the area being investigated has been removed. This may mean you can avoid having an operation under general anaesthetic (where you are given medication to make you sleep). 

Surgical excision biopsy

Sometimes a vacuum assisted excision biopsy is not possible. If this is the case, you will have a surgical excision biopsy under local or general anaesthetic.

Your surgeon may use dissolvable stitches placed under the skin. These will not need to be removed. However, non-dissolvable stitches will need to be taken out a few days after surgery. Your treatment team will give you information about this and about looking after the wound.

The operation will leave a scar, but this will fade over time.

Follow-up

If you have atypical hyperplasia, you may need follow-up such as yearly mammograms.

However, follow-up is on a case-by-case basis and depends on your individual circumstances and the arrangements at the hospital where you are treated. Your treatment team will let you know if and when you need follow-up.

If you have usual ductal hyperplasia

Having usual ductal hyperplasia can slightly increase your risk of developing breast cancer in the future. However, this risk is so small that you will not need treatment or follow-up.

It’s still important to go back to your GP if you notice any changes in your breasts, no matter how soon after your diagnosis of hyperplasia.

If you have atypical hyperplasia

If you have atypical hyperplasia, your risk of breast cancer is increased. Your treatment team will explain if and how you will be followed up.

If you’re worried about your risk of breast cancer, you can speak to your GP or treatment team.

Go back to your GP if you notice any changes, no matter how soon they appear after your diagnosis of atypical hyperplasia.