Intranuclear Inclusions in Multiple Myeloma and Macroglobulinemia

Inclusion bodies in plasma cell nuclei of six patients with multiple myeloma and of three patients with macroglobulinemia have been studied histochemically. In three cases they have been studied with the electron microscope. The inclusions are readily identified in Giemsa stained smears of bone marrow and in paraffin sections. Their PAS positivity may be related to the hexose content of the patient’s abnormal serum protein. Evidence is presented that the inclusions are true nuclear inclusion bodies, that they represent nuclear elaboration of glycoprotein, and that they may be found in all three immunoelectrophoretic varieties of multiple myeloma, as well as in macroglobulinemia.