Swollen or affected lymph nodes may sometimes need to be removed for examination. This is called lymph node biopsy.
Lymph node biopsy
A biopsy involves removal of whole or part of the lymph node to look under the microscope for signs of infection, or cancer.
Lymph nodes are filters located at intervals between the lymph channels. They function as part of the immune system and harbour the lymphocytes that act against the infections or foreign bodies.
Normally they are hard to feel. However when affected by an infection or cancer they may get bigger at the neck, back of the head, under the jaws and chin, behind the ears, groin or arm pits.
For a lymph node biopsy there may be several techniques the doctor may choose from. These include (1-4) –
- Fine-needle aspiration – a thin needle is inserted into the lymph node and a small sample tissue is taken out in a syringe.
- Core needle biopsy – A hollow needle with a special tip is inserted into the lymph node and a sample of tissue the size of a grain of rice is removed for examination
- Open biopsy or complete lymph node removal – For this procedure the site is cleaned with an antiseptic and a sterile surgical drape is placed over it.
The area is numbed using a local anesthetic injection. A small cut is made over the skin. The skin is then separated carefully from the underlying nodes. The surrounding tissue is carefully dissected away from the node. The surrounding nerves and blood vessels, especially in areas around the neck are avoided.
A needle with a suture is passed through the center of the node and traction is applied to it. The node is cut off gently. A single or more lymph nodes may be removed. If a single node is removed the procedure is to examine it under the microscope.
If more than one lymph node is taken, the biopsy is called a lymph node dissection. A lymph node dissection may be performed under wider anesthesia using regional anesthetic blocks or even under general anesthesia.
An open biopsy usually takes from 30 to 60 minutes. However if there is a lymph node dissection to remove cancer, the surgery may take longer. After the surgery the skin ends are sutured or stapled and the site is dressed.
When is lymph node removal required?
An open biopsy is needed in cases of (1-4) –
- Cancers – Lymphomas are cancers of the lymphatic system where there may be associated fever, fatigue, weight loss and excessive sweating at night.
- Staging of cancers. Many cancers, like breast cancer, spread via the lymphatic channels.
Examination of spread to the nearest lymph nodes can help the physician understand the extent of spread. This helps in staging the disease. For example, if there is extensive spread to the lymph nodes, the cancer may be of advanced stages.
- Cancer removal – sometimes lymph nodes that have been affected are removed completely to remove the cancer and prevent its further spread.
- A sentinel lymph node biopsy – This is usually the first lymph node to which cancer cells are most likely to spread from a primary tumor. It acts as a guard or sentinel to the affected organ.
A sentinel lymph node biopsy is used to determine the extent, or stage, of cancer in the body.
For sentinel lymph node biopsy of breast cancer an incision is made under the crease of the arm of the affected side. Usually it is done under general anesthesia along with removal of the tumor from the breast as well.
Complications of lymph node removal
Complications of lymph node removal include bleeding, pain, risk of infections of the operative site, injury of surrounding structures around the node like blood vessels, and nerves.
Sometimes mishandling of a cancerous node may lead to spread of tumor cells in the area of the biopsy or spread of infection from the node. (4)