Lymph node biopsies are an important tool for diagnosing and staging cancer. Your doctor will remove one or more lymph nodes near your known or suspected cancer. Then another doctor will examine the lymph node in the laboratory to see if it contains cancer cells.
What Is the Connection Between Cancer and Lymph Nodes?
Lymph nodes are an important part of your immune system. These small bean shaped structures are part of the immune system and they filter substances to fight infections. There are 100s of lymph nodes found throughout your body.
When the lymph nodes collect enough cancerous cells, they can become swollen and tender to the touch. That’s because they’re working hard to contain the threat.
If you have one or more swollen, tender lymph nodes, your doctor will explore several questions:
- How long has the lymph node been sore and/or swollen?
- Could other symptoms explain the swollen node? For example, do you have a runny nose or sore throat? That probably means your lymphatic system is fighting a cold or infection.
- Are other lymph nodes nearby also swollen or painful?
You’re most likely to feel swollen lymph nodes in your neck, groin, and underarms. Most other lymph nodes are usually too small or deep inside the body to feel.
Common illnesses and infections — not cancer — cause most swollen lymph nodes.
Why Would I Need a Lymph Node Biopsy?
Expect to need a lymph node biopsy if you’ve received a diagnosis of one of these cancers:
- Breast cancer.
- Gynecologic cancers.
- Head and neck cancer.
- Melanoma.
These cancers tend to spread into lymph nodes located near the main tumor. Lymph node biopsies are the only way to determine whether the cancer has spread. According to the National Institutes of Health, 34% of the lymph node biopsies performed showed malignant disease.
Types of Lymph Node Biopsies
There are several types of lymph node biopsies. Your doctor will let you know which one is right for you.
The type of cancer you have will determine the recommendation. The lymph node biopsy will help your doctor stage your disease and plan your treatment.
Fine needle aspiration biopsy
A fine needle aspiration biopsy is the least invasive type. It feels like getting blood drawn in the lab.
your doctor may perform this test in clinic or set up for image-guided biopsy by interventional radiology.
The doctor will insert a thin needle into the suspicious lymph node through your skin. Next, they will draw out some lymph fluid into a syringe. The doctor may need to insert the needle multiple times to obtain enough cells.
Experts in the lab will examine the fluid and cells. Your doctor will tell you what they found and develop a treatment plan.
Core needle biopsy
A core needle biopsy is similar to a fine aspiration biopsy, but the doctor uses a larger needle. The wider needle lets the doctor withdraw a chunk of tissue from inside the lymph node, not just fluid.
The doctor may need to insert the needle into different locations to get enough tissue. The laboratory will have more cells to work with, so a core needle biopsy can give more information than a fine needle aspiration biopsy.
Talk to your doctor about what you need to do to prepare for this test. You may receive light sedation in addition to a local anesthetic. If that’s the case, you may have to avoid eating or drinking until after the test.
With both types of needle biopsies, your doctor may use imaging equipment to help guide the procedure as needed. This equipment can include ultrasound, mammography, or MRI.
Open biopsy
Also known as a surgical biopsy, an open biopsy involves your doctor making a cut in your skin. The doctor then removes part or all of the suspicious lymph nodes and closes the surgical site using stitches or glue.
Talk to your doctor about pain management during the biopsy. You may receive sedation or general anesthesia.
When your doctor removes the entire lymph node, they perform what’s known as an excisional biopsy. If they remove only part of it, it’s an incisional biopsy.
Sentinel lymph node biopsy
Sentinel lymph node biopsy is most commonly used to help stage breast cancer and melanoma.
The sentinel lymph node is the first node to receive drainage from the tumor and is the most likely site for cancer to spread and metastasize.
Your doctor will identify the sentinel node by injecting a blue tracer dye and/or a nuclear medicine tracer near the tumor. The sentinel node is the first lymph node to turn blue. But sometimes, there’s more than one sentinel lymph node.
Your sentinel lymph node biopsy will include the following steps:
- Inject blue dye and/or nuclear medicine tracer near the tumor.
- Make a small incision in the skin above the sentinel node or nodes.
- Remove that lymph node — and any others that look suspicious.
- Send your tissue samples to the lab right away, where a doctor will check for cancer cells.
You will receive either spinal anesthesia with sedation or general anesthesia for the surgery. Either way, you won’t feel anything during the procedure. Some people find having the dye injected uncomfortable, but that’s just a brief part of the biopsy.
If your sentinel lymph nodes don’t contain cancer, you won’t need further lymph node surgery. Your doctor will use the sentinel lymph node biopsy results to design your breast cancer treatment plan.
If your sentinel lymph nodes do contain cancer, the results of this biopsy will direct your doctor on whether any further surgery or treatment is necessary.