Hodgkin lymphoma is a blood cancer. It is the most common form of blood cancer in teenagers and young adults.

Although it appears as a solid tumour in the glands (found in the neck, chest, armpit or groin), lymphoma is a blood cancer.

These glands, called lymph nodes, are a crucial part of our immune system that fights infection.

There are two main types of lymphoma: Hodgkin and non-Hodgkin. Hodgkin lymphoma is less common and tends to affect the lymph nodes in the head and neck. Most lymphomas are non-Hodgkin, which can affect any lymph node or related tissue in the body.

Hodgkin lymphoma is distinguished from other types of lymphoma by the type of cancer cell formed - the Reed-Sternberg cell - that is not found in any other blood cancer. 

Where in the body does Hodgkin lymphoma develop?

Hodgkin lymphoma is a cancer that develops in the lymph nodes, of the lymphatic system.

The lymphatic system is the network of vessels that runs throughout the body carrying fluid containing white blood and other important immune system cells. Lymph nodes respond to infections by releasing white blood cells called lymphoid cells into the blood stream to fight it off.

When someone has lymphoma, lots of abnormal lymphoid, or lymphoma, cells are produced within a particular lymph node.
 
These are the same cells that become cancerous in people who have leukaemia, another form of blood cancer. The difference is that leukaemia develops in the bone marrow and affects normal blood cell production. Lymphoma, on the other hand, develops in the lymphatic system and does not affect normal blood cell production.

In patients with Hodgkin lymphoma the cancer cells cluster in the lymph nodes and form tumours. These can also spill into the blood stream and spread the cancer around the body, including to other lymph nodes.

What are the signs and symptoms?