When Are Swollen Glands a Sign of Cancer in the Lymph Nodes?

‘Tis the season for runny noses and swollen glands (groan). More often than not, you can blame symptoms on a virus that’s spreading like wildfire.

But occasionally, a lump on the side of the neck can signal something more dangerous. In this Q&A, internist Daniel Sullivan, MD, explains when swollen glands may be a sign of cancer — and how to know if you’re at risk.

Q: What are lymph nodes, or glands?

A: In the neck, there are two areas that we call glands:

• The salivary glands provide saliva to the mouth to keep it moist. They’re under the jaw and on the side of our face.
• The lymph glands, also known as lymph nodes, are mostly on the side of the neck.

The lymph glands are the body’s sophisticated sewer system. They get rid of things that our body doesn’t want, such as bacteria, viruses and other things that enter our system.

There are about 600 pea- to bean-sized lymph nodes throughout your body, from your legs to your jaw.

Q: Why do lymph nodes sometimes swell up?

A: When a lymph node notices something harmful in the body, it uses its resources to try to destroy it. Inside the lymph nodes are blood cells that fight infection and disease. When the lymph nodes start using them, the gland gets bigger.

Colds, sore throats and ear infections all lead to swollen lymph nodes. We treat the infection, it goes away, and the lymph node shrinks.

Location matters: The glands under your jawline are rarely a problem. They may swell because one of the ducts of saliva entering the mouth gets narrowed or blocked. The chance of cancer developing on those glands is small. We’re more concerned about the lymph nodes on the side of the neck.

Q: When would swollen lymph nodes be a sign of cancer?

A: Often, lymph glands are painful when they’re swollen from an infection. We get concerned when someone has a lymph node in their neck that:

• Is enlarged (measuring 1 centimeter or more in diameter).
• Isn’t tender or painful.
• Isn’t getting better and has been there for longer than two weeks.

Two weeks is a rough guide for us to start considering cancer as a possibility. If it’s been there for more than two weeks and continues to get larger, that’s an even bigger red flag.

There are some other factors that may point to cancer:

• The patient’s background. Cancers are a little more common as we get into our middle years. The likelihood of cancer is higher in someone over 40 with swollen glands than in a 20-year-old.
• A history of skin cancer. If you had skin cancer that was treated, we’d consider the possibility that the cancer traveled beyond the skin.
• Lifestyle choices. We also pay attention to any lifestyle choices that raise the risk for cancer, including smoking and excessive alcohol use.
• Having HPV. The human papillomavirus, or HPV, is another factor that pushes the dial toward cancer. HPV is known for its risk for genital warts, but people can also develop HPV in their mouth or throat. That can lead to squamous cell cancer in the mouth or throat that can cause enlarged lymph nodes.

Q: What cancers are more often associated with swollen glands?

A: Squamous cell cancer is a big one. Skin cancers that started on the face or scalp can be a concern, too. And there are sometimes oral cancers that a dentist would recognize. If someone said to me, ‘A dentist once removed an early cancer from my mouth or cheek area,’ that may be a sign that something’s going on. We’d also consider lymphoma, cancer of the lymph nodes.

Patients’ health history is an important part of the conversation so we can plan the best next steps in their care.