Successful VEP-IFN-α Therapy in a Case of Non-Secretory Plasma Cell Leukemia (BJ-κ type)

Abstract

Plasma cell leukemia is a rare disorder with poor prognosis. We present a case of non-secretory primary plasma cell leukemia (Bence-Jones κ type), which was treated successfully by VEP-IFN-α therapy. A 82-year old man was admitted to Kanazawa Medical University in May 1991, because of emaciation and dehydration. Clinical findings showed decreased level of γ-globulin (IgG, IgA and IgM were all decreased armkedly), hypercalcemia, renal dysfunction and increased serum β-2 microglobulin. The peripheral blood leukocyte count was 30,100/μl with 64% plasma cells, and 80.4% plasma cells were also observed in the bone marrow. Only light chain-κ was detected in plasma cells by an immunohistochemical staining method, but immunoelectrophoresis showed no M-bow either in serum or urine. Electron microscopy revealed typical plasma cells with prominently developed rough endoplasmic reticulum. From these results, the diagnosis of non-secretory primary plasma cell leukemia was established. He was treated with VEP-IFN-α regimen, and plasma cells decreased markedly in both peripheral blood and bone marrow. Serum immunoglobulin recovered to within the normal range. After 6 courses of VEP-IFN-α, complete remission was achieved and the remission was maintained until he died of an unrelated event, bronchial obstruction due to misswallowing, in April 1992.