Abstract
A group of 62 B-cell malignant lymphomas and 6 cases of reactive lymphoreticular hyperplasia (RLH) in the gastrointestinal tract were investigated with morphological and immunohistochemical methods, and one-stage silver staining technique of nucleolar organizer regions.
Sixty-two cases of non-Hodgkin's lymphomas were reclassified using the updated Kiel classification, which was modified to include the categories low-and high-grade mucosa-associated lymphoid tissue lymphoma. There were 13 low 1-1 grade non-Hodgkin's lymphomas and 49 high 1-1 grade tumors. Low 1-1 grade lymphomas comprised mucosa-associated lymphoid tissue (MALT) lymphoma, three centrocytic (CC) lymphoma, six centroblastic-centrocytic (CB-CC) lymphoma and one plasmacytic lymphoma. High 1-1 grade lymphoma comprised 40 centroblastic, three immunoblastic, one lymphoblastic or Burkitt, four high 1-1 grade mucosa-associated lymphoid tissue (High 1-1 MALT) lymphoma, and one large cell anaplastic lymphoma (LCAL).
The presence of intracytoplasmic and/or surface immunoglobulins were studied by the immunoperoxidase technique using polyclonal antibodies. A monoclonal staining pattern as revealed by light chain restriction, was found in 10 cases (77%) of the low 1-1 grade non-Hodgkin's lymphomas, and in 43 cases (88%) of the high 1-1 grade lymphomas. MALT lymphomas were composed of cells containing intracytoplasmic or surface immunoglobulins that was exclusively IgM·κ. In addition, monoclonal antibodies, Ki-B3 and L26 gave positive staining of about 80% of B-cell lymphomas. MALT and CC lymphomas showed positive reaction with LN-2.
Using a silver staining technique, nucleolar organizer region-associated proteins (AgNORs) have been studied in paraffin sections of 6 RLH and 62 non-Hodgkin's lymphomas. Our data demonstrated that the mean number of AgNORs is related to the histological grade of non-Hodgkin's lymphoma. In addition, the mean AgNORs number of centroblast in RLH was greater than those of CC and MALT lymphomas. Therefore, this study showed that the AgNORs score which is an indicator of cellular proliferation may reflect the cell size. Furthermore, the mean number of AgNORs in the MALT lymphoma was similar to those of mantle zone and interfollicular lymphocytes in RLH. And this result may be closely related to the histogenesis of MALT lymphoma.
