3.  Marginal zone B-cell lymphomas  Marginal zone lymphomas are a group of slow growing B-cell lymphomas. They account 5% to 10% of lymphomas and tendto occur in people over the age of 60. The cells in these lymphomas look small under the microscope.There are 3 types of marginal zone lymphoma. Extra-nodal marginal zone B-cell lymphoma is also called mucosa associated lymphoid tissue lymphoma or MALT lymphoma-The most common site for MALT is the stomach due to infection of Helicobacter pylori.
Nodal marginal zone lymphoma-It also called monocytoid B-cell lymphoma which occurs within the lymph nodes sometimes can found in bone marrow. It makes up about 2% and more common in women than men over the age of 60.
Splenic marginal zone lymphoma-This is a rare type of lymphoma which associated with hepatitis-C virus infection. It starts in the spleen and can also be found in the bloodstream. This type makes up about 1% over the age 50.