Types of breast cancer and related breast conditions
Breasts are made up of:
fat
glandular tissue divided into lobes (each containing lots of lobules)
a network of ducts or milk ducts
connective tissue
The ducts spread from the lobes towards the nipple.
Atypical hyperplasia is when the cells in the breast increase in number and also develop an unusual shape. It can occur in the ducts (atypical ductal hyperplasia or ADH) or the lobules (atypical lobular hyperplasia or ALH).
Atypical cells mean that the cells are not entirely normal. Normal cells go through quite a few changes before they become cancerous.
The cells may not necessarily become cancer cells. The cells might not change further. Or they may die off or go back to normal.
Find out more about cells and cancer
Atypical hyperplasia can increase your risk of developing breast cancer in the future.
Atypical hyperplasia can sometimes develop as the breast changes with age. It can affect women of any age, but is more common in women over 35.
Atypical hyperplasia is usually found by chance after a routine mammogram. Or when tissue from a breast biopsy or surgery is looked at under a microscope in the laboratory.
Your specialist may recommend a small operation to make sure all of the hyperplasia is removed. Or you might have a vacuum assisted excision (VAE). You have VAE under local anaesthetic, so you are awake. Your makes a small cut in the skin. Then, using a vacuum assisted biopsy (VAB) device, breast tissue is removed. Your radiologist uses a mammogram or ultrasound to help them take all the tissue that is needed.
There is no danger that any of the cells will have spread if the cells removed are not cancer cells. But if the lump is left and becomes cancerous in the future, there is a risk that some of the cells could break away from the lump and spread elsewhere in the body.
Your specialist might want you to have follow up appointments. These may include clinic visits and a mammogram every one to two years. How often, and for how long you have follow-up appointments will depend on your situation.
Contact your doctor if you notice any new breast changes. You don't need to wait for your clinic visit.
Some factors can help to reduce the risk of breast cancer in general. These include:
being physically active
having a healthy diet and limiting the amount of alcohol you have
Last reviewed: 21 May 2026
Next review due: 21 May 2029
Breast cancer is now the most common cancer in the UK. Your risk of developing breast cancer depends on many factors including age, genetics and other factors such as obesity and alcohol.
There are some things that can help to reduce the risk of breast cancer, this includes keeping a healthy weight, eating a healthy diet and being physically active.
A mammogram is an x-ray of your breasts. This test helps to diagnose breast cancer and other breast conditions.
LCIS isn't cancer. LCIS means that some cells lining the lobules of the breast tissue have started to become abnormal.
There are different types of breast cancer and breast conditions, including breast cancer in men, and conditions related to breast cancer.
Find out about breast cancer, including symptoms, diagnosis, treatment, survival, and how to cope with the effects on your life and relationships.
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