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.
Institution
Department of Pathology, Jordan University of Science and
Technology, Irbid, Jordan. |