This information is about secondary cancer in the lymph nodes. This describes the situation where cancer cells have spread to the lymph nodes from a cancer that began elsewhere in the body.

The lymphatic system is one of the body's natural defences against infection. It is made up of organs such as the bone marrow, thymus and spleen as well as lymph nodes (sometimes called lymph glands) all over the body that are connected by a network of lymphatic vessels.

Cancer can develop in the lymph nodes in two ways. It can either start there as a primary cancer, or it can spread into the lymph nodes from a primary cancer elsewhere in the body. If cancer spreads into the lymph nodes from another part of the body, this is known as secondary or metastatic cancer. Cancer that starts in the lymph nodes themselves is called lymphoma.

This information is about secondary cancer in the lymph nodes. We have further information about the different types of lymphomas.

Cancerous tumours are made up of millions of cells. Some of these cells may break away from the primary cancer and travel in the bloodstream or the lymphatic system to another part of the body. They can stay dormant in such places for many years, or can grow into secondary tumours.

Cancer found in lymph nodes, in a part of the body far away from an original primary tumour, is usually recognised as being a secondary rather than a new primary cancer. Under a microscope, the cells will look like cells from the original type of cancer. For example, when a lung cancer has spread to the lymph nodes, the cells in the lymph nodes look like lung cancer cells.

In some people, when the original tumour is diagnosed, doctors will also remove some nearby lymph nodes. It is important to know whether or not a primary cancer has spread to any nearby lymph nodes, because it helps the doctors to estimate the risk of the cancer coming back, and to decide whether or not further treatment is necessary.

The most common sign of cancer cells in the lymph nodes is that one or more of the lymph nodes becomes enlarged or feels hard. However, if there are only a small number of cells in the lymph nodes, they may feel quite normal, and it is only possible to tell that a cancer is present by removing part, or all, of the lymph node and examining the cells in a laboratory. However, it is important to remember that lymph nodes can be enlarged for other reasons, such as infections.

If the lymph glands are deep inside chest or abdomen, they may cause pressure on surrounding organs or structures. This can lead to symptoms like breathlessness or backache.

Sometimes a lymph node, or group of nodes, may appear larger than they should be on a scan, such as an ultrasound scan, CT scan or MRI scan. This may be a sign that there is a secondary cancer in the lymph nodes.

Sometimes a CT scan or MRI scan is all that is needed to make a diagnosis of secondary cancer in the lymph nodes, but for other people it may be necessary to carry out further tests. For example:

Excision biopsy This involves removing a lymph node, or nodes, under general anaesthetic.

Needle biopsy A sample of cells may be taken from an enlarged lymph node, using a fine needle attached to a syringe. The needle biopsy is usually done in a clinic and does not need a general anaesthetic.

The cells can then be sent to a laboratory to be examined under the microscope by a pathologist (a doctor who can diagnose illness by looking at cells).

If your doctors feel that the enlarged lymph nodes (or those seen on a scan) are quite clearly linked to the primary cancer, it may not be necessary to remove a node or take a biopsy.

The treatment for a cancer that has spread to the lymph nodes depends on the individual situation, including the person's general health and type of primary cancer. It may include surgery, chemotherapy, radiotherapy, hormonal therapy, or a combination of these treatments.

Sometimes, cancer cells may be found in lymph nodes near to the primary tumour, which have been taken away during surgery to remove this cancer. In this situation, treatment such as chemotherapy may be suggested. This is because if a primary cancer has spread to the nearby lymph glands, it increases the risk that the cancer may have spread to other parts of the body (even though those glands have been removed). Chemotherapy and/or hormonal therapy can reduce the chance of the cancer coming back for some people.

Learning that your cancer has spread, or come back, can be a shock. You may have many different emotions, including anger, resentment, guilt, anxiety and fear. These are all normal reactions, and are part of the process many people go through in trying to come to terms with their illness.

Each individual has their own way of coping with difficult situations; some people find it helpful to talk to friends or family, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is available if you need it.

Our cancer support service can put you in touch with counselling services in your area or see our list of counselling organisations.

This section has been compiled using information from a number of reliable sources including:

• Oxford Textbook of Oncology (2nd edition). Eds Souhami et al. Oxford University Press, 2002.
• Cancer and its Management (5th edition). Eds Souhami and Tobias. Oxford Blackwell Scientific Publications, 2005.

For further references, please see the general bibliography.