Why does metastatic cancer cause swollen lymph nodes?

Swollen Lymph Nodes is a common presentation of Metastatic Cancer. Lymph nodes filter fluid and help coordinate immune responses. Cancer cells may move from a nearby tumour into the lymphatic system or arrive from a more distant site. The affected node can become larger, firmer, or less mobile as cells and surrounding tissue change.

Infection and inflammation also commonly enlarge lymph nodes, sometimes with tenderness, warmth, sore throat, or fever. A clinician considers the node's location, duration, texture, associated symptoms, and cancer history. Examination, imaging, blood tests, or a tissue sample may be used when needed; the swelling alone cannot establish its cause.

Note where the swelling is, when you first noticed it, whether it is changing, and whether it is painful. Tell your doctor about fever, night sweats, unexplained weight change, skin changes, or a recent infection. Avoid repeatedly pressing or massaging the node, which can make the area sore. If you have a cancer diagnosis, report a new lump to the treating team so they can decide whether it needs examination or imaging.

Get urgent help if neck swelling causes difficulty breathing or swallowing, if you develop sudden facial or arm swelling, or if swelling comes with severe weakness or confusion. Arrange prompt review for a node that continues to enlarge, feels hard or fixed, or appears without an obvious infection. The right timing depends on your symptoms and medical history.

Could this node be reacting to infection, treatment, or cancer? Which examination or scan would clarify it? Would a sample be useful? What changes should I monitor, and which breathing or swallowing symptoms require immediate help?