The lymphatic system is made up of thin tubes (vessels) that branch into all parts of the body. These carry lymph, a watery fluid containing white blood-cells called lymphocytes. At various points in this network are groups of small, bean-shaped organs called lymph nodes, which make and store infection-fighting cells. The spleen, thymus and tonsils are also part of the lymphatic system.

A normal lymphocyte will divide, and stop dividing, in response to certain chemical signals. However, if a lymphocyte is damaged, it may continue to divide uncontrollably, producing a growing mass of abnormal cells. This mass is a lymphoma: a tumour that can cause blockages and displace normal cells and tissue.

Lymphomas commonly involve the lymph nodes, and so may be found where there are clusters of these: in the underarms, groin, pelvis, neck, chest and abdomen. Because lymphatic tissue is so widespread, however, lymphomas can start in almost any tissue or organ, and abnormal lymphocytes can spread to almost any part of the body, including the brain, spinal cord, bone, liver, ovaries, testes and digestive tract.

Hodgkin's and non-Hodgkin's lymphomas


Lymphomas are divided into two general types: Hodgkin's lymphomas and non-Hodgkin's lymphomas (NHL).

Adult Hodgkin's disease most commonly affects young adults and people older than 55; it may also be found in patients with HIV/Aids. Hodgkin’s disease can also occur in children.

NHL is a large, much more diverse group of lymphomas that do not have the typical appearance of Hodgkin’s disease. NHL occurs five times more often than Hodgkin’s, and can be found in children and adults. It is a particular threat to people with suppressed immune systems.

NHL has high-grade and low-grade variants. Low-grade lymphomas develop slowly and are more widespread through the body. They are rarely curable, although chemotherapy can put the cancer in partial or complete remission, which can last for many years.

High-grade lymphomas are very aggressive (fast-developing) cancers. If left untreated, they will cause the death of the patient within a few months. However, they often involve only specific groups of lymph nodes and are sensitive to treatment, and are thus potentially curable.

Symptoms


 These may include:

    • Painless swelling of the lymph nodes in the neck, underarm, or groin

    • Fever

    • Night sweats

    • Tiredness

    • Weight loss without dieting

    • Itchy skin



Further symptoms depend on which areas of the body are affected and on the specific type of lymphoma.

Swollen lymph nodes do not always indicate the presence of lymphoma. Certain infections and systemic illnesses (rheumatoid arthritis, sarcoidosis etc.) can also produce enlarged lymph nodes.

Diagnosis


Seek medical attention if symptoms persist for longer than two weeks. A doctor will carefully check for swelling or lumps in the neck, underarms and groin, and for other symptoms.

To prove that a mass is lymphoma requires a biopsy (tissue sample). Sometimes enough material can be obtained using a thin syringe, but in most cases, the doctor will cut a sample from the mass with a scalpel, under anaesthetic. A surgeon may need to remove an entire lymph gland. The sample is sent to a laboratory and examined under a microscope for cancerous cells.

Before treatment can be started, additional tests and scans may be needed to confirm the subtype of lymphoma and its stage (the extent of spread) – from Stage I, involving a single lymph node region, through to Stage IV:  widespread disease, frequently involving the bone marrow. 

Treatment


All lymphoma patients can benefit from treatment. Many lymphomas are curable, or can be put into partial or complete remission, which can last for many years.

However, not all lymphomas can be cured, and treatments commonly have unpleasant side effects. Certain lymphomas can come back after treatment, or recur in other areas of the body. Some patients eventually develop other cancers as a result of their treatment, and should visit a doctor regularly to be checked.

The choice and effectiveness of treatment depends on the type of lymphoma, its location, size and stage, as well as the patient's symptoms, age, sex and physical condition. Two main types of treatment are used:

    • Chemotherapy (using drugs to kill cancer cells and shrink tumours)

    • Radiation therapy (using high-dose X-rays or other high-energy rays to kill cancer cells and shrink tumours)



Chemotherapy is the mainstay of treatment, but combination therapy (chemo- and radiation therapy) is also frequently used. Radiation therapy only is restricted for use in patients with very early-stage disease.

Chemotherapy drugs may be taken by pill, or intravenously. Chemotherapy is called a systemic treatment because the drugs enter the bloodstream and kill cancer cells throughout the body.

In addition:

    • Biological therapy – sometimes called biological response modifier (BRM) therapy, biotherapy or immunotherapy – is a relatively new treatment technique. This attempts to boost, direct or restore the body's own immune-system defences.

    • Bone marrow transplantation is an option for certain patients who require very high chemotherapy doses, as this destroys the patient's bone marrow.



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