What is non-Hodgkin lymphoma?

Non-Hodgkin lymphoma (NHL) is a cancer of the lymphatic system.

NHL is the fifth most common cancer in the UK. Around 11,500 people are diagnosed with it each year. There are many types of NHL. Some grow very slowly and may not need treatment for months or years. In some cases they may never need treatment. Other types grow quickly and need treatment soon after diagnosis.

How does non-Hodgkin lymphoma develop?

NHL, like other types of cancer, is a disease of the body’s cells.

The body is made up of cells that need to be replaced as they age or are damaged. This happens by cell division, which is when a cell divides and makes a new copy of itself.

Normally, cell division is carefully controlled so the right amount of cells is made to meet the needs of the body. However, if this process gets out of control for some reason, too many cells are made and a cancer can develop.

In NHL, blood cells called lymphocytes become abnormal. These abnormal lymphocytes (lymphoma cells) keep dividing and grow out of the body’s control. Over time, the number of lymphoma cells increases and they form a lump called a tumour.

The most common place for this to happen is in the lymph nodes. But, NHL can begin in almost any part of the body including; the stomach, small bowel, skin, tonsils, thyroid or testicles. Lymphoma that grows outside the lymph nodes is called extranodal lymphoma.

Because lymphocytes travel around the body, NHL can spread from where it first started. It can spread through the lymphatic system from lymph nodes in one part of the body to lymph nodes elsewhere. Lymphoma cells can also travel in the bloodstream to organs such as the bone marrow, liver or lungs. When the lymphoma cells reach a new area, they may carry on dividing and form a new tumour.

Back to Understanding non-Hodgkin lymphoma

What is cancer?

There are more than 200 different kinds of cancer, each with its own name and treatment.

The lymphatic system

To understand lymphoma, it helps to learn how the lymphatic system works.

Types of non-Hodgkin lymphoma

There are many types of non-Hodgkin lymphoma. These are often described as B-cell or T-cell – depending on where they began.