[MALT-lymphoma].

Gastric lymphoma is most frequently an extranodal marginal zone-B-cell-lymphoma of mucosa-associated lymphoid tissue (MALT). The diagnosis is established by biopsy of the tumor. Computed-tomography, endosonography and recently capsule-endoscopy are used for staging. It is a relative new finding that MALT-lymphomas of the stomach are induced by Helicobacter pylori. A side-effect-poor breakthrough has been achieved by eradication of this bacterium with antibiotics. Refractory cases are amenable to radiotherapy, chemotherapy or surgical resection. The rarer aggressive lymphomas of the stomach are treated primarily by chemotherapy and radiotherapy. For both entities a further improvement may be achieved in ongoing prospective clinical trials by addition of the monoclonal antibody rituximab, which targets CD20 on lymphoma cells.