How common are swollen lymph nodes in metastatic cancer?

Lymph nodes are small immune-system structures found in areas such as the neck, armpit and groin. When cancer has spread, nearby or more distant nodes may enlarge. The pattern depends on where the original cancer began and how it has travelled through the body.

An enlarged node can also occur with an infection, inflammation or another non-cancer condition. Its size, location, texture and change over time cannot by themselves establish why it is enlarged. A clinician may combine an examination with scans, blood tests or a sample from a node when clarification is needed.

If you have a new or persistent swelling, arrange a medical assessment. Note where it is, when you first noticed it, whether it is changing, and any associated symptoms such as fever, night sweats, tiredness, unexplained weight change or pain. Bring a list of medicines and any previous cancer diagnosis or treatment to the appointment.

If you are already being treated for cancer, tell your oncology team about a newly enlarged area. They can decide whether it needs examination, imaging or another follow-up plan.

Seek urgent medical care for swelling that is rapidly worsening, trouble breathing or swallowing, severe pain, a high fever, or redness and warmth that is spreading. These features need prompt assessment regardless of the cause. For a lump that persists or is growing without urgent symptoms, book a routine clinical review rather than trying to diagnose it at home.

Ask which lymph-node areas are involved, what other explanations are being considered, and whether an examination, scan or biopsy would help. If you have a known cancer, ask how the finding fits with your current treatment plan and what change should prompt you to contact the team earlier.