Marginal zone lymphoma: types, symptoms, diagnosis and treatment

Marginal zone lymphoma develops when the body makes abnormal B lymphocytes. Cancer Research UK says it develops in an area at the edge of lymphoid tissue called the marginal zone and is usually slow growing. Around 2,600 people are diagnosed with marginal zone lymphoma in the UK each year according to the same source.

The three types differ in where they begin. MALT lymphoma, also called extranodal marginal zone lymphoma, starts in the mucosa, the soft moist tissue layer covering organs, most commonly in the stomach but sometimes in the small bowel, salivary gland, thyroid gland, tear glands or lungs. Nodal marginal zone lymphoma starts within lymph nodes and accounts for fewer than 10% of cases. Splenic marginal zone lymphoma starts in the spleen and makes up around 20%. A fourth, primary cutaneous type starts in the skin.

In most cases it is not known what causes nodal marginal zone lymphoma. Lymphoma Action says it is more common in people who have been infected with hepatitis C virus or who have some autoimmune conditions, but that the vast majority of people with hepatitis C or autoimmune conditions do not go on to develop lymphoma. It is most common in people over 50.

Cancer Research UK notes that splenic and nodal types are more common in people with hepatitis C, in which case antiviral treatment is given, and Lymphoma Action says clearing the infection might also clear the lymphoma, so no further treatment may be needed. Gastric MALT lymphoma is linked to H. pylori infection.

Some people have no symptoms. Cancer Research UK says nodal and splenic types can cause general B symptoms, and that other symptoms depend on the type.

• Painless swellings in the neck, armpit or groin from enlarged lymph nodes (nodal type).

• Discomfort or pain in the upper tummy, reduced appetite and weight loss from an enlarged spleen (splenic type).

• Tiredness or breathlessness from anaemia, and bruising or bleeding from low platelets, if bone marrow is affected.

• Heavy night sweats, temperatures that come and go and losing more than one tenth of your weight (B symptoms).

• Symptoms specific to the organ involved if it is a MALT lymphoma, which depend on where it starts.

Cancer Research UK says the main test for nodal marginal zone lymphoma is a lymph node biopsy, in which part or all of a swollen node is removed and examined under a microscope. Splenic marginal zone lymphoma can usually be diagnosed from a blood or bone marrow sample, and rarely the spleen is removed to make the diagnosis, an operation called a splenectomy.

Further tests may include a CT scan, bone marrow test, and less commonly a PET-CT scan. Lymphoma Action points out that nodal marginal zone lymphoma can be difficult to diagnose because it can look similar to other lymphomas, that you will have blood tests including for hepatitis C, and that it is often advanced (stage 3 or 4) by the time it is diagnosed. About 1 in 3 people have lymphoma cells in the bone marrow.

Cancer Research UK says treatment depends on the type of marginal zone lymphoma, where it is, symptoms and general health. The main options are radiotherapy, immunotherapy on its own, chemotherapy combined with a targeted immunotherapy drug (chemoimmunotherapy), surgery to remove the spleen for splenic types, and targeted cancer drugs.

You might not have treatment straight away. Cancer Research UK explains that you have regular check-ups instead, perhaps every few months at first, which may become less frequent if you are well and nothing changes, with an examination and blood tests. Treatment might start if you have symptoms such as low blood cell levels, a very large spleen, lymph nodes that are increasing in size, or B symptoms.

Lymphoma Action states that delaying treatment in this way does not affect how well it works when you do need it, or how long you might live.

Lymphoma Action says nodal marginal zone lymphoma develops slowly, treatment is often successful but the lymphoma often relapses and needs more treatment to keep it under control, and most people live with this type for many years. Cancer Research UK adds that low grade lymphomas can sometimes change into a faster-growing lymphoma, called transformation, and that this is treated like high grade lymphoma.

Lymphoma Action puts transformation at fewer than 1 in 10 people. If it is suspected you will usually have a biopsy and a PET/CT scan.

Diagnosis and treatment take place in NHS haematology services, with a multidisciplinary team and a clinical nurse specialist as your main contact. For gastric MALT lymphoma, treatment of H. pylori is part of the care described by Cancer Research UK.

Private haematology is available for second opinions and faster consultations, and some people use it alongside NHS follow-up. Treatment decisions follow the same guidance in both.