Richter's transformation of lymphoma complicating Gaucher's disease

A case of lymphoma in a middle-aged woman with Gaucher's disease, a mu-kappa monoclonal gammopathy, peripheral lymphocytosis, and massive splenomegaly is described. There was no evidence of Gaucher's disease in the splenectomy specimen. Instead, the splenic architecture was effaced by a small lymphocytic lymphoma (SLL), with a few foci of large cell lymphoma (LCL). Immunoperoxidase studies showed that both lymphomatous components had a mu-kappa immunophenotype. Flow cytometric analysis of peripheral blood and spleen lymphocyte surface markers confirmed monoclonality. The intensity of surface immunoglobulin expression and the results of other cell marker studies in the SLL component were consistent with a stage of differentiation beyond that typical of chronic lymphocytic leukemia (CLL). The presence of abundant cytoplasmic immunoglobulin in the SLL and the association with monoclonal gammopathy were more consistent with Waldenström's macroglobulinemia or plasmacytoid lymphocytic lymphoma. The immunohistochemical and flow cytometric findings suggest that the SLL component evolved clonally or underwent Richter's transformation to LCL. Although Gaucher's disease has been associated with a variety of B-cell disorders, the subsequent transformation to a high-grade lymphoma has not been previously reported.