Mucosa-associated lymphoid tissue lymphoma
What is mucosa-associated lymphoid tissue lymphoma (MALT)?
MALT is a form of a non-Hodgkin lymphoma called marginal zone lymphoma. MALT lymphoma accounts for approximately 8% of non-Hodgkin lymphoma (NHL) cases, making it the third most common type of NHL. These lymphomas are usually slow-growing and remain, often for a long time, in the area in which they first developed.
How does MALT lymphoma affect the body?
MALT lymphoma develops in the lymphoid tissue, in the mucosa or tissue that lines body organs, or in body cavities including: the gastrointestinal tract (usually stomach, but can also occur in the small bowel or colon); lungs; eyes; skin; salivary glands; thyroid gland; and breasts.
Who does MALT lymphoma commonly affect?
MALT lymphomas can occur at any age but typically affect people in their 60s. It is more common in women than in men.
Do we know what causes MALT lymphoma?
Many people with MALT lymphoma of the stomach (gastric MALT lymphoma) have been infected with the bacterium Helicobacter pylori (H. pylori). Bacterial or viral infections have also been linked to other MALT lymphomas. People with MALT lymphomas in areas other than the stomach often have a history of autoimmune diseases such as Hashimoto’s thyroiditis (lymphoma in the thyroid gland), and Sjögren’s syndrome (lymphoma in the body’s moisture-producing glands- sweat, tear and salivary). The causes of MALT lymphoma in other parts of the body are not known.
How is MALT lymphoma treated?
Treatment is tailored to the type, stage and grade. Most slow-growing, localised MALT lymphomas respond well to treatment. Local therapies such as radiation therapy or surgery are used with early stage MALT lymphomas that occur in areas other than the stomach. More advanced MALT lymphomas (stage 3 or 4) are usually treated with chemotherapy regimens such as CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) or CVP (cyclophosphamide, vincristine and prednisolone), or with single-agent chemotherapy such as chlorambucil. The monoclonal antibody, rituximab may also be used, either on its own or in combination with chemotherapy. People with gastric MALT lymphoma who are infected with H. pylori can achieve lengthy remission in most cases, once the infection is effectively treated with antibiotics. These work to shrink the lymphoma. Drugs that lower the production of acid in the stomach such as ranitidine may also be given in conjunction with antibiotics. People with gastric MALT lymphoma which is not progressing may be observed without being treated initially. This is known as the ‘watch and wait’ approach.