Chronic lymphatic leukemia developing in a patient with multiple myeloma. Immunologic demonstration of a clonally distinct second malignancy

Abstract

A patient with multiple myeloma who subsequently developed chronic lymphocytic leukemia is reported. Initial studies demonstrated clinical and hematological features of multiple myeloma with an IgM λ paraprotein. Skeletal disease was a significant presenting feature, although relapse occurred in extraosseous sites, particularly the pleura. He developed chronic lymphatic leukemia 31 months later and immunological studies showed the malignant lymphocytes to have k (Kappa) light chain surface immunoglobulin, demonstrating separate clonal origin of this patient's two B-cell malignancies.