MALT lymphoma (also known as MALToma) is a tumor disease, which belongs among the group of lymphomas. As other diseases in this group, MALT lymphoma develops from lymphocytes. The lymphocytes are a subtype of white blood cells, which take an important part in proper function of the immune system.
The abbreviation MALT means mucosa associated lymphoid tissue. Lymphatic tissue located in the mucous membranes is of great importance to maintain local defense and mucosal protection layers against microorganisms. Under certain circumstances, it is this lymphatic tissue, out of which the lymphoma grows.
MALT lymphomas usually arise when the mucosa is affected by a chronic inflammatory process. It can be either infectious or noninfectious inflammation including the autoimmune processes. The most common is MALT lymphoma of the stomach, which usually occurs due to chronic stomach inflammation caused by Helicobacter pylori. Despite the fact that this bacterium lives in stomachs of a high portion of the population, the Helicobacter-induced MALT lymphoma is quite rare. Other possible causative factor is chronic irritation of small intestinal mucosa by celiac disease.
It depends on the site of localization of MALT lymphoma. Gastric MALToma usually causes chronic digestive problems including nausea and loss of appetite. Symptoms of advanced stages of MALT lymphoma may be identical to classic symptoms of lymphomas (recurrent fevers, night sweats, weight loss).
The diagnostic procedure also depends on the location of lymphoma. Gastric and duodenal MALT lymphomas are well-detectable by upper GI endoscopy that enables the doctor to take tissue samples for histological examination. In stomach MALT lymphoma, it is necessary to confirm the presence of Helicobacter pylori. MALT lymphomas in the small intestine may be found by capsule endoscopy or by double-balloon enteroscopy and MALT lymphomas of the large intestine can be diagnosed colonoscopically.
MALT lymphomas have an overall good prognosis and they tend to disappear when their causative factor (i.e. the cause of inflammation) is removed. Stomach MALT lymphomas are often cured just by eradication of Helicobacter pylori by antibiotics. The therapy of a MALT lymphoma itself includes classical chemotherapy.