A firm, round, fluid-filled swelling within the breast tissue
- Most common between the ages of 30 and 50
- Genetics and lifestyle are not significant factors
A breast cyst is a firm, round lump in the breast tissue that forms when a lobule (the part of the breast that produces milk) fills with fluid. The development of cysts is influenced by levels of female sex hormones. Breast cysts most often affect women aged 30–50, particularly those approaching the menopause.
A cyst may be felt just under the skin or may occur deeper within the breast tissue. Cysts are usually not painful, although some can be and the pain can come on suddenly.
Breast cysts may occur singly, but in about half of all cases there is more than one cyst, and both breasts may be affected. Some women also have generalized lumpiness of the breast tissue.
You should always consult your doctor if you detect a lump so that the possibility of breast cancer can be investigated. In rare cases, cancerous cells may be found in the wall of a cyst.
What might be done?
The usual treatment is to drain the cysts of fluid (see Fine-needle aspiration of a breast lump), which may then be examined for cancerous cells. Cysts usually disappear after aspiration but may recur, requiring further drainage. If cysts recur frequently, they may be removed surgically, but this is not usually necessary.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.