MALT lymphoma is a type of non-Hodgkin lymphoma (NHL). It often starts in the lining of the stomach or intestine. This lining is called the mucosa and this gives the lymphoma its name, the initials MALT standing for mucosa associated lymphoid tissue.
From a practical viewpoint doctors divide all the various types of NHL into one of three groups: low grade, high grade or intermediate grade. This division is based on the appearances under the microscope and helps predict how the condition will behave.
Low grade NHLs usually have a relatively slow growth rate, running a long course and often needing little or no treatment for months or possibly years. When they do need treatment they respond well but are likely to come back again at some time in the future. They frequently respond to treatment on several occasions over the years but may eventually become resistant or transform to a high grade form of NHL.
High grade types of NHL usually grow more rapidly and behave more aggressively and so need immediate treatment. Despite this they are more likely to be completely cured than low grade NHLs. Around half of all people with high grade forms of NHL will be cured by the use of intensive chemotherapy.
Intermediate types of NHL lie somewhere between these two extremes in their behaviour.
MALT lymphomas usually behave as a low grade, or more indolent, lymphoma although sometimes changes to a high grade, more active form of the disease, are seen.
Most cases of MALT lymphoma affecting the stomach are associated with infection by a bacterium called Helicobacter pylori (often abbreviated to H. pylori). When tests show the bacterium is present in the tumour tissue then a course of intensive antibiotic treatment will sometimes lead to a remission of the lymphoma.
For those patients with MALT lymphomas of the stomach where there is no evidence of H. pylori, or where antibiotics do not clear the condition, then surgery, radiotherapy or a combination of the two can be used or chemotherapy depending upon individual circumstances. These too are very successful with a majority of patients being cured.
When the MALT lymphoma involves the lung or the bowel then chemotherapy is usually given. This is often relatively simple treatment, sometimes just using a tablet, called chlorambucil. Once again treatment is usually very successful. Occasionally more aggressive forms of the lymphoma occur which require more intensive chemotherapy which still cures many patients.