What is MALT lymphoma?:
MALT lymphoma is an uncommon form of Non-Hodgkin Lymphoma (NHL). MALT stands for 'Mucosa-Associated Lymphoid Tissue'. Unlike most other lymphomas that occur in lymph nodes (or lymph glands), this lymphoma arises from lymph tissue present in the lining of some other organs of the body.
MALT lymphoma is also medically known as an extranodal marginal zone B-cell lymphoma. That simply means that it is a type of B-cell NHL that arises not from nodes but other organs.
Who is affected by MALT Lymphoma?:
MALT lymphomas account for only about 5% of all Non-Hodgkin lymphomas. They are more common in older adults, but may occur in individuals in their twenties and thirties. It is slightly more common in women than in men.
Which organs of the body are affected?:
The most commonly affected organ is the stomach, which accounts for nearly 2 out of every 3 cases. But other organs are also affected by MALT lymphoma. The lung, thyroid, salivary glands and the eye may also be affected by this lymphoma.
What causes MALT lymphoma?:
MALT lymphomas of the stomach are associated with a bacterial infection. Helicobacter pylori is a type of bacteria that commonly infects the stomach and causes ulcers and gastritis. In some individuals it can also cause MALT lymphomas. The cause of MALT lymphomas in other organs is not well understood.
How does MALT lymphoma behave?:
MALT lymphomas are low grade lymphomas. They grow slowly and remain confined to one organ for a relatively long time. The majority of patients with MALT lymphoma are diagnosed early, before the disease has spread to other organs and lymph nodes.
What are the symptoms of MALT lymphoma?:
The symptoms of MALT lymphoma depend on the organ affected. When MALT lymphoma affects the stomach, you may feel indigestion, weight loss and black stools because of bleeding into the stomach. Some people may feel a vague pain in the abdomen.
Tests for MALT lymphoma:
To diagnose a MALT lymphoma, the doctor will need to take a biopsy from the tumor. For MALT lymphomas of the stomach this usually involves an endoscopy. Doctors will also test for the presence of the H pylori in the stomach. Other tests that will need to be performed include blood tests, scans of the abdomen and chest, and also a bone marrow test.
Staging of MALT lymphomas:
The staging of lymphomas is explained in the article Understanding Lymphoma Staging. MALT lymphomas do not arise in lymph nodes, nor do they commonly spread to other organs. Most MALT lymphomas are diagnosed in Stage IE. Only about 20% of MALT lymphomas are in advanced stage at diagnosis.
Treatment of MALT lymphomas:
Treatment of MALT lymphomas depend on the organ involved and the stage of diagnosis. In most patients local treatments like radiation or surgery may be adequate to deal with the disease. Chemotherapy may not be required if the disease is in an early stage. For MALT lymphomas of the stomach, treatment for H pylori infection may also effectively control the disease. For a better understanding of the treatment of MALT lymphomas of the stomach, see the article Gastric MALT Lymphoma Treatment.