[Small lymphocytic lymphoma during the course of pure red cell aplasia]

A 29-year-old woman was diagnosed as having pure red cell aplasia (PRCA) in 1983. Her serum and IgG inhibited erythroid colony formation of bone marrow cells from a normal individual, suggesting antibody-mediated suppression of erythropoiesis. She was first successfully treated with corticosteroids, azathiopurine and cyclophosphamide. However, she relapsed in 1995 and her anemia became refractory to immunosuppressive therapy. In 1998, she developed systemic lymph node enlargement and was diagnosed as having B-cell small lymphocytic lymphoma. Combination chemotherapy resulted in regression of the lesion, but failed to improve the anemia. In this patient's case, we can speculate that B cells producing autoantibodies against erythroid cells have undergone transformation, or alternatively that the immunosuppressive state caused by the PRCA therapy promoted generation of a neoplastic B cell clone.