[CD5- CD11c+ CD23- small lymphocytic lymphoma evolving from aplastic anemia].

ABSTRACT

A 91-year-old woman was hospitalized with acute respiratory distress syndrome due to pneumonia in June 1997. Since she had pancytopenia and a bone marrow aspirate indicated hypocellularity with no increase in myeloblasts, dysplasia or abnormal chromosomes, aplastic anemia (AA) was diagnosed. Pulse therapy with methylprednisolone and antibiotics proved successful, and blood cell numbers stabilized. In June 2001, she was readmitted to our hospital with persistent low grade fever and leukopenia. A bone marrow aspirate from the sternum and iliac bone biopsy revealed compact proliferation of small lymphocytes, and the surface marker CD5- CD10- CD11c+ CD19+ CD20+ CD23- was detected through immune staining and flowcytometry. CD30+, CD34+and CD56+cells were scarce. Tests for surface immunoglobulins, IgG, IgA, IgM and IgD, were negative. No nodal or extranodal lesions were evident. Since Southern blot analysis of bone marrow cells indicated rearrangement of the immunoglobulin heavy chain and abnormal chromosomes were evident, small lymphocytic lymphoma (SLL) was diagnosed. Four intravenous infusions of rituximab (375mg/m2) were administered without critical adverse effects. Tests conducted four weeks later revealed saturation of CD20+ antigens of lymphoma cells and chromosomal abnormalities and rearrangement of the immunoglobulin heavy chain were still apparent. Though complete remission of the pancytopenia was not achieved, serum concentrations of lactate dehydrogenase and soluble interleukin-2 receptor decreased, and the numbers of platelets and erythrocytes increased. There was also an improvement in systemic condition. This was a rare case of SLL having the surface marker of CD5- CD10- CD11c+ CD19+ CD20+ CD23-, which had evolved from AA and infiltrated bone marrow.