plasma cell leukemia, an unusual neoplasm of blood-forming tissues in which the predominant cells are plasmacytes. The disease may develop with multiple myeloma or arise independently. Bence Jones proteinuria, abnormal serum globulins, hepatomegaly, and splenomegaly are usual in plasma cell leukemia. In most cases plasma cell leukemia is fatal, but some patients respond to treatment with alkylating agents and glucocorticoids.
