Their growth seems to be dependent upon continuous stimulation of the immune system by an infectious agent, such as H. pylori, or some other entity, termed an antigen, that the body recognizes as foreign.
MALT lymphomas are generally indolent, that is, they grow slowly and cause little in the way of symptoms.
It is not known if infectious agents also cause MALT lymphomas outside of the stomach.
MALT lymphomas are then recognized as areas of inflammation or ulceration within the stomach.
MALT lymphomas occur at a frequency of about 1.5 per 100,000 people per year in the United States and account for about 10% of all non-Hodgkin's lymphomas.
This antigen-driven growth permits these tumors to be treated by eliminating the stimulus that generated the original, normal immune response.
Those MALT lymphomas that arise in the stomach in response to H. pylori infections are generally successfully treated with antibiotics, which eliminate the bacteria.
MALT lymphomas are solid tumors that originate from cancerous growth of immune cells that are recruited to secretory tissue such as the gastrointestinal tract, salivary glands, lungs, and the thyroid gland.
it is standard practice that patients presenting with MALT lymphomas should be evaluated in a similar manner to individuals with nodal lymphomas, the more common type of lymphoma that originates at sites within the lymphoid system.
In some cases, such as in the thyroid, MALT lymphomas seem to arise in patients who have autoimmune diseases, which make their immune systems treat their own tissue as foreign or antigenic.
The frequency varies among different populations. For example, in parts of Italy the frequency of MALT lymphomas is as high as 13 per 100,000 people per year.
In the United States, where infections with H. pylori are quite common, less than 1 in 30,000 people who have H. pylori in their stomachs develop MALT lymphomas.
The frequency varies among different populations. For example, in parts of Italy the frequency of MALT lymphomas is as high as 13 per 100,000 people per year.