Intranuclear inclusions in multiple myeloma and macroglobulinemia.

By GEOFFREY M. BiurriN, YASUKAZU TANAKA AND GEORGE Biuicim n M ANY DISTINCTIVE inclusion bodies have been described in the plasma cells of inflammatory and neoplastic diseases and in plasma cell tumors. Most of these structures have been in the cytoplasm of the plasma cell, and hematologists are familiar with Russell bodies,’ Mott cells,’ “grape cells,”2 “morula cells,”3 and crystalline precipitates.4’5 In addition, Sorensen has recently described inclusions resembling viral particles in the cytoplasm of plasma cells of a case of multiple myeloma.6 There are only a few reports of inclusions in plasma cell nuclei,713 and some of these structures actually represent cytoplasmic invaginations.’4 Various authors have attributed diagnostic significance to intranuclear inclusions in plasma cells.12’13 It is the purpose of this report to present evidence that inclusions in plasma cell nuclei may be of nuclear origin, that they may represent nuclear elaboration of protein, and that they may be found in several immunoelectrophoretic varieties of multiple myeloma as well as in macroglobulinemia.