Specialist Surgeon | Female Health Care | Cape Town Mediclinic
A sentinel lymph node biopsy checks whether breast cancer has reached the lymph nodes in the armpit by removing only the first nodes that the breast drains to. If these nodes contain no cancer cells, further treatment to the lymph nodes is usually not needed. Removing as few nodes as possible reduces the risk of arm swelling and of arm and shoulder stiffness.
What Is a Sentinel Lymph Node?
The sentinel nodes are the first lymph nodes that lymph fluid drains to from the breast. Some people have more than one sentinel node, and more than one may be removed.
Why Are the Lymph Nodes Checked?
Whether cancer cells are present in the lymph nodes influences the choice of further treatment. The lymph nodes are usually checked as part of breast cancer surgery, with either a lumpectomy or a mastectomy.
How Are the Sentinel Nodes Found?
One or more of the following is used:
- Radioactive tracer: a small amount is injected into the breast before surgery, and a handheld probe locates the nodes that have taken it up.
- Blue dye: injected into the breast during the operation, staining the sentinel nodes blue.
- Magnetic tracer: a liquid containing tiny iron particles, detected with a magnetic probe.
The nodes are removed through a small incision in the armpit and examined for cancer cells. Blue dye may temporarily colour the urine and leave blue staining around the injection site.
What Happens After the Result?
- No cancer cells in the sentinel nodes: further treatment to the lymph nodes is usually not needed.
- Cancer cells found: further surgery to remove the remaining lymph nodes, or radiotherapy to the armpit instead, may be offered. This is decided with the oncology team.
Who Has a Sentinel Lymph Node Biopsy?
It is used when the armpit ultrasound, or a needle sample from the armpit, is normal. If a needle biopsy of the lymph nodes has already found cancer cells, removal of the armpit lymph nodes (axillary clearance) is usually recommended instead.
Frequently Asked Questions
How many lymph nodes are removed?
Only the sentinel nodes. Some people have more than one, and more than one may be removed.
Why not remove all the lymph nodes?
Removing as few nodes as possible reduces the risk of arm swelling (lymphoedema) and arm and shoulder stiffness.
Will the blue dye stain my skin?
Blue dye can leave staining around the injection site for some time, and can temporarily colour the urine.
When will I know the result?
Your surgeon discusses the result with you once the nodes have been examined, along with any further treatment.
If you have been diagnosed with breast cancer and would like to discuss your surgery, please arrange a consultation with Dr. Loots.
Book a ConsultationThis article provides general information only and does not constitute medical advice. If you are concerned about your health, please seek advice from a doctor.