What is a cyst?
A cyst is a swelling with liquid in it. A blister is a type of cyst.

Breast cysts form from the milk ducts. The milk ducts are tiny tubes for draining the milk from the breast tissue to the nipple. There are often dozens of tiny cysts throughout the breasts, giving a honeycomb appearance. Usually only one or two cysts will swell to a size where they can be felt. Cysts often appear suddenly, even quite big ones and can sometimes be uncomfortable.

What causes cysts?
We do not know exactly why cysts form. They are commonest between the ages of thirty and fifty, but HRT may extend the age band. They are rare when periods stop.

What can be done?
A cyst hardly ever means anything serious. However, if a swelling feels like a cyst then we would confirm this by arranging for an ultrasound scan of the breast and sometimes a mammogram. Cysts often resolve without treatment, but sometimes your doctor will insert a needle into the cyst to draw off the fluid. Once the fluid has been removed the cyst should disappear. There may be some bruising of the skin for a day or two and sometimes this can cause some thickening where the cyst was. You will be given an appointment to return to clinic in about four to six weeks to check that the cyst has not refilled, and that any thickening has resolved.

There is a chance of about one in five that you will notice one or more cysts in the future. If this happens, then you should report it to your doctor so that he can check that it is definitely another cyst and not anything else.

If you require further advice or information please contact the
Macmillan Breast Care Nurses, Hazel Ricard and Hilary Rickwood on 020 8565 5885