Gastrointestinal lymphoma

Gastrointestinal lymphoma occurs in many forms, some characteristic of their location. The most common form is extranodal marginal zone lymphoma of MALT type, usually abbreviated to MALT lymphoma. This entity recreates the structure and cytological features of normal mucosa-associated lymphoid tissues. In the stomach this is associated with infection by Helicobacter pylori. Three translocations are implicated in the development of MALT lymphoma, t(1;14), t(11;18) and t(14;18). These interfere with the normal pathways of Bcl-10 and MALT-1. Enteropathy-type intestinal T-cell lymphoma represents one end of a spectrum of disorders including refractory sprue and ulcerative jejunitis characterized by a proliferation of phenotypically abnormal mucosal T-cell clones. Some cases arise as a complication of long-standing coeliac disease but most present in adulthood. A history of nutritional problems and loose stools may indicate refractory coeliac disease.