Localized involvement of other sites can be treated with radiation or surgery.[70,71,72,81,82,83] Patients with extragastric MALT lymphoma have a higher relapse rate than patients with gastric MALT lymphoma in some series, with relapses many years and even decades later. Many of these recurrences involve different MALT sites than the original location. When disseminated to lymph nodes, bone marrow, or blood, this entity behaves like other low-grade lymphomas.[61,86] A prospective, randomized trial of 252 patients with nongastric, extranodal MALT compared chlorambucil with rituximab plus chlorambucil. With a median follow-up of 62 months, the event-free survival was better for the rituximab arm (68% vs. 50%, P = .002), however, the 5-year OS was 89% in both arms.[Level of evidence: 1iiDi] This trial was extended with a third arm using rituximab alone, the results of which are not yet available. For patients with ocular adnexal MALT, antibiotic therapy using doxycycline targeting Chlamydia psittaci resulted in durable remissions for half of the patients in a small series of 27 patients.[Level of evidence: 3iiiDiv] Large B-cell lymphomas of MALT sites are classified and treated as diffuse large cell lymphomas.
Monocytoid B cell lymphoma (Nodal marginal zone lymphoma)
Patients with nodal marginal zone lymphoma (monocytoid B-cell lymphoma) are treated with the same paradigm of watchful waiting or therapies as described for follicular lymphoma. Among patients with concomitant HCV infection, the majority attain a complete or partial remission after loss of detectable HCV RNA with treatment using interferon-alpha with or without ribavirin.[Level of evidence: 3iiiDiv]
Mediterranean abdominal lymphoma
The disease variously known as Mediterranean abdominal lymphoma, heavy–chain disease, or immunoproliferative small intestinal disease (IPSID), which occurs in young adults in eastern Mediterranean countries, is another version of MALT lymphoma, which responds to antibiotics in its early stages.Campylobacter jejuni has been identified as one of the bacterial species associated with IPSID, and antibiotic therapy may result in remission of the disease.
Splenic marginal zone lymphoma
Splenic marginal zone lymphoma is an indolent lymphoma that is marked by massive splenomegaly and peripheral blood and bone marrow involvement, usually without adenopathy.[92,93,94] This type of lymphoma is otherwise known as splenic lymphoma with villous lymphocytes. Splenectomy may result in prolonged remission.[62,95]