Gastrointestinal lymphoma: prevention and treatment of early lesions.

Gastrointestinal lymphomas comprise a group of distinct clinicopathological entities. Differences in lifestyle and environmental factors between countries could account for the variety in the distribution of the main subtypes: low-grade B-cell lymphomas of the mucosa-associated lymphoid tissue type, alpha-chain disease and enteropathy (coeliac disease)-associated T-cell lymphoma (EATL). The possibility of preventing these lymphomas implies a knowledge of their natural history together with an identification of potential predisposing factors. The development of the lymphoid hyperplasia and subsequently low-grade lymphoma with the possibility of high-grade transformation is a multifactorial process involving both antigenic and host-related factors. The pathogenic role of Helicobacter pylori and gluten has been demonstrated in gastric lymphoma and enteropathy-associated T-cell lymphoma respectively, while environmental factors, especially non-specific bacterial ones, may play a major role in the pathogenesis of alpha-chain disease. The most difficult task in preventing these lymphomas is the recognition of early lesions likely to regress after the removal of the exogenous stimulus.