Lymph node biopsy

Lymph nodes are small, bean-shaped filters found throughout the body, in the neck, armpits and groin, and deep in the chest, belly and pelvis. They trap germs and hold immune cells that fight infection. When they are busy fighting, they swell. That is why your neck glands get tender with a sore throat.

Most swollen lymph nodes are caused by infection and shrink on their own within a few weeks. Less often, a node swells because of an immune condition such as sarcoidosis, a lymphoma (cancer of the immune cells), or cancer that has spread from another place, such as the skin, breast, lung, head and neck or gut.

On ultrasound, a normal lymph node is oval with a bright center, like a kidney bean. A node that is round, has lost its bright center or has unusual blood flow is more concerning and may need a biopsy.

Your doctor weighs your age, your symptoms, how the node feels and how it looks on a scan. A node that goes away within a few weeks rarely needs more than watching. A biopsy is more likely to be recommended when:

Enlarged nodes deep inside the chest or belly are usually found on a CT or PET scan. These also often need a sample, since they cannot be felt or watched by hand.

When someone is referred for a swollen node, I first look at it with ultrasound myself. Many times I can reassure them that it looks like a reactive node, one fighting an infection, and suggest a follow-up instead of a needle. When it does look concerning, I aim for the most abnormal part and take enough tissue for lymphoma testing on the first visit.

Fabio Komlos, MD, interventional radiologist · About Dr. Fabio Komlos

A core needle biopsy gives enough tissue for a diagnosis in most people, including for many lymphomas. A fine needle aspiration (FNA), which draws out cells, can be enough to confirm cancer that has spread from a known source. Sometimes the pathologist needs the whole node to classify a lymphoma, and surgery is then recommended.

1. 1
   Getting ready

   You lie in the position that gives the safest path to the node. For deep nodes, a nurse starts an IV and gives moderate (twilight) sedation.

2. 2
   Finding the node

   We find the node with ultrasound for nodes in the neck, armpit or groin, or with CT for deeper nodes. We clean and numb the skin.

3. 3
   Taking the samples

   We guide the needle into the node and take several samples. You feel pressure and may hear a click. Some samples go into a special fluid for lymphoma testing.

4. 4
   Finishing up

   We remove the needle, press on the site and apply a small bandage or skin glue.

1. Right after
   Rest for 30 minutes to 2 hours, depending on how deep the node was and whether you had sedation.
2. Rest of the day
   Take it easy. No driving if you had sedation. You can shower the next day.
3. Days 1–3
   Mild soreness and a small bruise are common. Most people return to normal activities the next day.
4. First week
   Avoid heavy lifting after a deep node biopsy.

Results usually take 2 to 5 business days. Lymphoma testing, such as flow cytometry and special stains, and cultures for infections like tuberculosis can take longer, sometimes a few weeks. The results go to the doctor who ordered the biopsy.

Needle biopsy of a lymph node is very safe. A small bruise is common. Serious bleeding and infection happen in fewer than 1 in 100 people. Depending on where the node is, there is a small risk of injury to nearby structures. For nodes in the chest this includes an air leak around the lung (pneumothorax). Sometimes the sample does not give a firm answer, and a repeat biopsy or surgery is needed.