What is a sentinel lymph node biopsy for breast cancer?

Sentinel lymph node biopsy is a procedure to see if your breast cancer has spread and reached the lymph nodes.

Lymph nodes are bean shaped and are a part of lymphatic system that carried lymph (fluid). Lymph nodes are present all over the body including neck, armpits, groin, etc. When breast cancer cells become malignant and spread out of breast tissue, they travel through lymph to sentinel lymph nodes in the armpits.

During SLNB (sentinel lymph node biopsy), a sentinel lymph node is taken out and checked for cancer cells. Weather they’re found in the lymph node or not helps the doctor in deciding the treatment and management options in your particular case.

What happens during an SLNB?

The sentinel lymph node biopsy is done under general anesthesia usually, making the patient unconscious during the procedure.

There are two techniques used to find the sentinel lymph node

Blue dye

During this procedure, a blue dye is injected into the breast near the cancerous part while the patient is unconscious inside operation room. The blue dye travels to the sentinel lymph node through lymph and turns it blue.

A radioactive substance

For this procedure, a radioactive substance is injected before going into the operating room, into the breast near the cancerous part and colored area around nipple. Then, the doctor uses a special device to locate the sentinel lymph nodes using the radioactive substance while you’re unconscious.

Most surgeons use either one of the techniques while some may use both of them to be sure. Once the sentinel lymph node has been located, a small incision is made to take them out. A pathologist examines the lymph node for cancer spread.

If cancerous cells are seen in the sentinel lymph node, other lymph nodes around in that area are biopsied too.

What happens after an SLNB?

After the SLNB procedure, you might feel pain, hematoma, bruising or infection in that area and is covered by painkillers or other required medicines.

If the blue dye method was used during the procedure, your breast may remain blue till the dye is removed completely from the body. You may also have green urine for a day.

Rarely, people might be allergic to the SLNB dye. In case of allergy, the intravenous medication is injected right away to control the reaction.

The radioactivity of the radioactive substance used in second method is very low and leaves your body through urine quickly without any harm. You don’t become radioactive or harmful to people around you.