Non-Hodgkin's lymphoma is cancer that starts in the lymphoid tissue. Such tissue makes up the lymph nodes, spleen, and other organs of the immune system.

White blood cells called lymphocytes are found in lymph tissues. Most lymphomas start in a type of white blood cells called B lymphocytes.

For most patients, the cause of the cancer is unknown. However, lymphomas may develop in people with weakened immune systems. For example, after an organ transplant.

Non-Hodgkin's lymphoma is grouped, or staged, according to how fast the cancer spreads. The cancer may be low grade, intermediate grade or high grade. Burkitt's tumor is an example of a high-grade lymphoma. There are many different types of non-Hodgkin's lymphoma.

According to the American Cancer Society, a person has a 1 in 50 chance of developing non-Hodgkin's lymphoma. Most of the time, this cancer affects adults. However, children can get some forms of CLL. High-risk groups include those who have received an organ transplant or who have a weakened immune system (immunosuppression). The cancer is more common in men than women.

Non-Hodgkin's lymphoma can cause a variety of symptoms. Symptoms depend on what area of the body is affected by the cancer. Symptoms may include:

• Swollen lymph nodes in the neck, underarms, groin, or other areas (may occur as an armpit lump)
• Fever
• Excessive sweating with night sweats
• Unintentional weight loss
• Severe itchiness

Coughing or shortness of breath may occur if the cancer affects the thymus gland or lymph nodes in the chest, which puts pressure on the windpipe.

Some patients may have stomach pain or swelling, which may lead to a loss of appetite, constipation, nausea, and vomiting.

If the cancer affects cells in the brain, the person may have a headache, concentration problems, personality changes, or seizures.

The doctor will perform a physical exam and feel lymph nodes to see if they are swollen. Tests to diagnose and stage non-Hodgkin's lymphoma include:

• Lymph node biopsy
• Bone marrow biopsy
• CBC with differential
• CT scans of the chest, abdomen and pelvis
• Blood chemistry tests
• X-rays
• PET (positron emission tomography) scan