If you discover a breast lump on self-exam or if a nodule or density is detected when you have a mammogram, you may then need to have an ultrasound performed on that area of the breast. This targeted breast ultrasound can detect differences in breast tissue density and the doctor can see the following, if they are present:
- Fluid-filled sacs, called cysts
- Solid breast masses
- Abnormalities in breast architecture (suspicious changes to the normal breast anatomy)
If necessary, based on the findings, ultrasound can also be used as a guide to help your doctor perform aspirations of a cyst or perform a needle biopsy. If an ultrasound results in a suspicious finding, further tests will be required to determine whether the lesion is noncancerous (benign) or cancerous.
Prior to a cyst aspiration, local anesthesia (topical skin injection) will be used to numb the skin and breast tissue. If the mass appears to be a fluid-filled cyst or if a water-filled cyst has already been identified, a needle on a syringe will be guided into the cyst and the fluid will be withdrawn. This procedure is called an ultrasound-guided cyst aspiration. Not all cysts need to be drained, and the decision is made together by the patient and their physician.
The physician will make sure that the cyst can be completely aspirated (drained) using ultrasound. If the fluid removed appears concerning (for example, bloody), it can be sent to a pathologist who will examine it under a microscope (cyst cytology). If the cyst cannot be completely aspirated, then the physician may recommend tissue sampling using a needle biopsy or surgical excision. Biopsy samples may also be recommended when a physician detects a solid growth within the cyst.
Core biopsy tissue samples can also be obtained using ultrasound guidance, which helps to ensure adequate sampling of the suspect area in the breast. This sampling is also performed using local anesthesia. If needed, the patient may be given a pill to help them relax during the biopsy procedure.
Once the core biopsy tissue samples are obtained, the physician will place a small metallic clip or other marker inside the breast to mark the biopsy site. This clip or marker can be seen on subsequent breast imaging studies (for example, mammography, MRI, or ultrasound). It verifies that the suspect area initially identified is the same area that was biopsied. Localization markers also serve a critical role in patients who are diagnosed with breast cancer as they assist the surgeon in pinpointing the cancer during surgery. This is very important for small cancers that cannot be felt and for patients who are treated with chemotherapy before breast cancer surgery. The cancers of some patients who have undergone chemotherapy will “disappear” (called a complete pathological response) such that the location of the breast cancer can only be verified by the localization marker.
Whenever possible, it is preferable for suspicious breast findings to have needle biopsies (core biopsies) rather than open surgical biopsies. Often the needle biopsy shows that the area of concern is not cancerous and surgery is not necessary. In the cases where the needle biopsy reveals cancer, all breast cancer treatment options are available to the patient. And the patient will go to surgery only for breast cancer treatment rather than requiring a trip to the operating room for breast cancer diagnosis and another trip to the operating room for breast cancer treatment.