[Gastrointestinal lymphomas].

Non-Hodgkin lymphomas affecting extranodal tissues can be primitive or secondary. The area most frequently involved is the gastrointestinal tract. MALT-type lymphomas are B-cell lymphomas characterized by small cells originating from the lymphoid tissue of the mucosa. The criteria for a correct diagnosis of extranodal lymphomas are morphological, but include immunophenotypic and immunogenotypic analysis. Gastrointestinal lymphomas consist of B-cell and T-cell lymphomas. B cell-lymphomas include: small cell B-lymphomas, large cell B-lymphomas, immunoproliferative small intestinal disease; multiple lymphomatous polyposis, follicular lymphomas, B-cell lymphomas centrocytic type. T-cell lymphomas include enteropathy-associated and non enteropathy-associated lymphomas.