Primary gastrointestinal lymphomas in Jordan are similar to those in Western countries.

It has been a common practice to divide gastrointestinal (GI) lymphomas into Western and Middle Eastern types; the former predominantly involves the stomach, whereas the latter are mostly intestinal. Recent studies suggested that these lymphomas are biologically different from their nodal counterpart and hence should be classified separately. In this retrospective study, we examined all of the primary GI lymphomas seen at Jordan University Hospital, Amman, Jordan, between 1983 and 1992 in an attempt to reclassify and immunophenotype these cases. We studied 53 cases of primary GI lymphomas for which available material was found. Lymphomas were morphologically reclassified according to current classification schemes. Immunoperoxidase stains were performed using the streptavidin biotin method using antibodies against leukocyte common antigen, B, and T-cells. The stomach was the most common site of involvement, accounting for 62% of the cases. The male-to-female ratio was 2.8:1. The three most common histologic types were, in order, diffuse large cell lymphoma, Burkitt's lymphoma, and lymphoma of mucosa-associated lymphoid tissue. Immunoproliferative small intestinal disease was seen in only one patient. The B-cell phenotype predominated in our cases; it was seen in 85% of the gastric and 100% of the intestinal cases. Unlike other series from the region, the stomach was the most commonly involved site by GI lymphoma. Immunoproliferative small intestinal disease seems to be a rare entity in Jordan, and the majority of intestinal and gastric lymphomas were diffuse large cell lymphomas. Histopathologic evidence of mucosa-associated lymphoid tissue origin was seen in at least 18% of the gastric cases. B-cell lymphomas were by far the most common type seen, and T-cell lymphomas were rare.