[The clinical features and tumor cells characteristics of splenic marginal zone lymphoma].

OBJECTIVE

To deepen the understanding of splenic marginal zone lymphoma (SMZL) and improve the level of diagnosis and therapy.

METHODS

A typical case of SMZL, a 61 year old female with lymphocytosis and splenomegaly found fortuitously, was reported. The pathologic, immunologic and genetic features of tumor cells in peripheral blood, bone marrow and spleen were studied with light microscopy, phase contrast microscopy, scanning electron microscopy, immunohistochemical method, flow cytometry, G chromosome banding technique and PCR for studying the pattern of IgH gene rearrangement.

RESULTS

The spleen was large with uniform parenchyma and smooth surface. There were multiple small gray-white nodules on sections. Histologically, the neoplastic cells replaced the marginal and mantle zones with complete replacement of germinal centers in the white pulp. The neoplastic cells were predominantly of small to medium size with oval or slightly irregular nuclei. Lymph nodes in the splenic hilum were infiltrated by tumor cells. Immunophenotypic analysis demonstrated that the lymphocytes in the bone marrow expressed CD(20), HLA-DR, CD(45) RA and bcl-2. The monoclonal pattern of IgH gene rearrangement in peripheral blood and bone marrow was found to be the same as that in spleen. After splenectomy, COP chemotherapy and IFNalpha-2a were given and the abnormally increased lymphocytes decreased to normal level. Seven months later the monoclonal rearranged immunoglobulin heavy chain gene pattern changed to polyclonal pattern.

CONCLUSION

Splenomegaly, lymphocytosis in peripheral blood and bone marrow without lymph node enlargement and leukocytosis are clinical characters of SMZL. Presence of monoclonal rearranged IgH gene is in favor of the diagnosis. Splenectomy should be done earlier in suspicious patients to avoid malignant transformation.