Pathological and immunohistochemical study of gastrointestinal lymphomas with detection of chromosomal translocation t [11;18] by fluorescence in situ hybridization

ABSTRACT

Twenty seven cases of primary gastrointestinal non-Hodgkin's lymphoma [GI-NHL] selected from a total of 57 archived specimens with the same diagnosis during the period from January 2000 to December 2006. Of the 57 studied specimens [28/57] 49.1% had gastric lymphoma, while 29/57 [50.9%] had intestinal localization. Cases were classified histopathologically as 21 diffuse large B cell lymphoma. 15 Mucosa Associated Lymphoid Tissue [MALT], 7 diffuse large cell lymphoma with concomitant areas of MALT, 10 Burkitt's lymphoma, 2 Mantle lymphoma, 1 immunoproliferative small intestinal disease [IPSID] and 1 lymphoplasmacytic lymphoma Immunohistochemical staining using 2 monoclonal antibodies; CD20 [L-26] as B-cell marker and CD45 RO [UCHL-1] as T-cell marker whenever needed. FISH technique was used to detect chromosomal translocation t [11; 18]. FISH was done using the locus specific identifier [LSI] dual colour, dual fusion AP12/MALTI probe on 27 cases. Six of the cases [22.2%] were scored positive for translocation t [11;18] [q21;q21]. 5/6 of the positive cases were located in the stomach and only 1/6 had small intestinal location. All the six positive cases were subclassified as MALT lymphoma. The results recommended that translocation t [11;18] [q21;q21] appears to have a role in GI MALT lymphoma, but further investigations in a larger number of series are warranted to clarify this hypothesis. FISH technique can be expected to become an important simple tool for diagnosis and management of MALT lymphoma