Breast Cysts

Breasts cysts are fluid filled collections with a cell lining and are benign.  Cysts may  present as a lump or may be found on a mammogram or ultrasound as a mass.  If large and tense they may cause pain. Cysts are very common and increase in incidence leading up to menopause.  Beyond menopause, as oestrogen levels drop, cysts become less common. Some women may develop many cysts. The exact cause of cysts is not well understood but relates to fluid building up and causing ducts to swell in a localised area.

Cysts are easily diagnosed on ultrasound as a well-defined mass of fluid density (black centre on ultrasound) and generally needle biopsy is not required for the diagnosis. Sometimes the cyst may have some irregularity on ultrasound, termed a complex cyst and so needle biopsy may be performed to confirm its nature. If a cyst is painful it can be easily drained with a needle under ultrasound guidance and surgery is not required.

Breast cysts do not increase a woman’s chance of getting breast cancer.  It is not feasible to prevent cysts as they occur naturally.