UW Health radiologists offer breast ultrasound as a diagnostic procedure.
Why Breast Ultrasound?
When an abnormality is found on a mammogram or is discovered by physical examination of the breast, it is very important to determine whether the abnormality is normal tissue, cystic (fluid filled) or solid. Almost all simple breast cysts are benign (non-cancerous). Mammography alone is unable to tell the difference between a cyst and a solid mass.
Breast ultrasound is a simple and painless method to distinguish whether an abnormality discovered on mammography or physical examination is normal tissue, cystic or a solid mass.
Ultrasound uses high-frequency sound waves to image the structures in the breast. A transducer is placed on the skin over the breast together with a clear gel to allow the transducer to closely contact the skin. The transducer is a microphone-like device which sends and receives sound waves. These sound wave patterns are displayed as an image of the breast tissue on a screen.
- A simple cyst is seen on the screen as a round or oval black structure in a background of grainy gray material, which is the ultrasound appearance of normal breast tissue. Although benign, some cysts can be painful or they can be large enough to be bothersome.
- Some cysts contain debris or areas of solid tissue; these are referred to as “complicated” cysts. Complicated cysts have some increased chance, although small, of being cancerous. In addition, some complex cysts can disguise themselves by looking like a solid mass. Ultrasound–guided cyst drainage may be recommended by your doctor or by the radiologist in order to relieve pain caused by the cyst or to evaluate a complex cyst further.
During ultrasound-guided cyst aspiration, the skin over the cyst is cleaned and numbed with local anesthetic. The radiologist identifies the cyst using ultrasound. A thin needle is directed into the cyst and the cyst is drained. If the cyst drains completely, no other procedure is needed. If the cyst does not drain (and is therefore considered a solid mass), either surgical “excisional” biopsy or ultrasound-guided needle biopsy should be performed.
Ultrasound–guided cyst drainage only takes a few minutes and causes very little discomfort. If necessary, several cysts can be drained at the same time.
A solid abnormality is seen on the screen as a gray structure. A solid abnormality should be further evaluated. This could be done by inserting a small needle to try to draw fluid out of the abnormality, by biopsying the abnormality, or by having your doctor watch the lesion over time to see that it doesn’t change.