Marginal zone lymphomas are indolent b-cell lymphomas that account for approximately 12 percent of all b-cell lymphomas. The median age for diagnosis is 65. There are three types of marginal zone lymphoma.
The first, extranodal marginal zone lymphoma of mucosa-associated lymphatic tissue (MALT) occurs outside the lymph nodes, such as in the stomach, small intestine, salivary gland, thyroid, eyes, and lungs. MALT is divided into two categories: gastric MALT, which develops in the stomach, and non-gastric MALT, which develops outside of the stomach. For gastric MALT lymphoma, the initial treatment generally is antibiotic therapy, which is typically given for two weeks. Approximately 70 percent to 90 percent of patients respond to antibiotic therapy and approximately half of the patients require no further treatment. If patients relapse after antibiotic therapy, there are additional treatment options available, including: bendamustine (Treanda), bortezomib (Velcade), various chemotherapies, low dose radiation, rituximab (Rituxan), and surgical excision. Non-gastric MALT treatment typically includes surgery or radiation therapy with or without a system-wide approach, such as chemotherapy.
Nodal marginal zone lymphoma (sometimes called monocytoid b-cell lymphoma) occurs within the lymph nodes. Splenic marginal zone lymphoma occurs mostly in the spleen and blood. Nodal marginal zone lymphoma is usually a slow-growing disease and often a patient is on watch and wait. When treatment is necessary, options include radiation therapy and/or chemotherapy. Several treatment options exist for splenic marginal zone lymphoma. Some patients have the spleen removed or are given low-dose radiation of the spleen. Other patients may receive rituximab (Rituxan) with or without chemotherapy such as fludarabine, cladribine, or cyclophosphamide. Several other treatments are under investigation.
