What is diffuse large B-cell lymphoma (DLBCL)?

This in turn affects your lymphatic system and immune system, which are both part of your body’s natural defence against infection.

In DLBCL, abnormal lymphocytes gather in lymph nodes (glands) or organs and cause lumps or swellings. The symptoms you have depend on how big the lumps and swellings are, and where they are in your body.

Your doctor will need to check which type of NHL you have, because the treatments for each type are different. Your doctor will also classify the lymphoma based on your symptoms and where it is in your body. This is called the ‘stage’ of the lymphoma and it helps your healthcare team plan your treatment.

We have more information on the lymphatic and immune systems.

Over 10,000 people are diagnosed with a type of NHL every year in the UK. About a third of these people have diffuse large B-cell lymphoma (DLBCL).

In most cases, we can’t say what causes DLBCL. But there are some factors that could make you more likely to develop it:

• Age: DLBCL is more common in older people. Children rarely get DLBCL, but some other types of high-grade NHL are slightly more common in children.
• Sex: Men are slightly more likely than women to develop DLBCL – we don’t know why.
• Family history: Having a close relative with DLBCL may increase your chances of developing it. We don’t know why. If you’re worried about this, your healthcare team are the best people to speak to.
• Infections: Some viral infections, including the human immunodeficiency virus (HIV), the human T-cell leukaemia/lymphoma virus (HTLV-1) and the Epstein-Barr virus (EBV) can increase the risk of someone developing DLBCL and other types of NHL.
• Transformation of low-grade NHL: In some people, low-grade NHL can transform into a high-grade version. Each year, around 3% of cases of a low-grade NHL called follicular lymphoma (three cases in every 100) will transform to high-grade NHL, usually to DLBCL.

It's important to realise that there's nothing anyone could have done to stop themselves getting DLBCL. You can’t catch lymphoma, or pass it on to someone else.