Until recently, breast ultrasound was considered only a "supplementary examination" to mammography or for diagnosing lumps found in manual examinations. However, in recent years, the perception has changed, and now breast ultrasound is often performed in addition to mammography. Nevertheless, in age groups where mammography is recommended, ultrasound does not serve as a substitute.
Ultrasound is a medical imaging technique that allows the visualization of body tissues by emitting and receiving sound waves toward and from the tissues. The examination does not involve radiation. Some growths that are not detected in mammography may be diagnosed using ultrasound, especially in the early stages of the disease, hence the importance of the examination. Women at high risk add ultrasound to their routine follow-up. The examination is also essential for women with dense breast tissue, as it might be challenging to obtain information from mammography, even though they are not at an increased risk.
Uses of breast ultrasound:
The examination allows the characterization of lumps found in manual examinations and mammography. Unlike mammography, ultrasound can distinguish between solid lumps and cysts (fluid-filled spaces). Ultrasound can also differentiate between simple cysts, which are unrelated to cancerous growths, and complex cysts with septations or solid components, which may indicate pre-cancerous or cancerous findings.
Differentiating between benign and malignant findings: Generally, a cancerous lump appears differently in mammography. There are additional sonographic (sound) characteristics specific to cancerous lumps. However, a sonographic (or mammographic) benign appearance does not definitively indicate a non-cancerous finding. Cancerous findings with benign sonographic appearance tend to behave less aggressively than other growths.
Is the "lump" indeed a lump? In women with fibrocystic breast tissue, ultrasound can distinguish between thickened breast tissue and a lump. Therefore, ultrasound can be used when a woman has very fibrocystic breasts and the manual examination is not conclusive. However, not every woman with fibrocystic breasts requires an ultrasound. The decision depends on the examining surgeon's confidence in the accuracy of the examination.
Ultrasound is efficient in detecting problematic lymph nodes. Breast cancer involvement may occur through affected lymph nodes in the armpit, even in the absence of findings in the breast. Ultrasound is more effective than manual examination in identifying abnormal lymph nodes. Therefore, breast ultrasound includes an examination of the armpit lymph nodes.
When a cancerous breast tumor is being evaluated, ultrasound can identify affected lymph nodes. Lymph nodes can be biopsied through a fine-needle aspiration, which can help assess the severity of the disease before surgery and improve the quality of surgical and medical treatment. Additionally, ultrasound may identify additional growths not visible in mammography, which can improve the accuracy of surgical and medical treatment.
Since routine imaging follow-up for women carrying genetic mutations starts at an early age when mammography is less effective, it is recommended to include annual mammography and ultrasound examinations and one breast magnetic resonance imaging (MRI) examination per year. We recommend performing the tests alternately every six months.