Coexistence of Polycythemia Vera and Biclonal Gammopathy (γGK and γAL) with Two Bence Jones Proteins (BJK and BJL)

A patient with long standing polycythemia vera, who was treated with P³², chemotherapy and phlebotomies recently developed a myeloma-like disease picture. Two paraproteins (γG type K and γA type L) were found in the serum together with two Bence Jones-like proteins in the urine (kappa and lambda). γM was increased to twice the normal value.

Immunofluorescence studies of the bone marrow showed two clones of plasma cells each of which produced only one type of heavy chain. No cells with double fluorescence were seen. The two types of immunologically different plasma cells were morphologically indistinguishable from one another.