Reactive plasmacytic lesions of the bone marrow.

A consecutive series of 1,000 bone marrow aspirates was analyzed for percentage of plasma cells, incidence of plasmacytic satellitosis, associated clinical disease states, lymphoid follicles, lipid granulomas, hemosiderin content, and various combinations thereof. Plasmacytosis was a common finding, and tended to parallel the presence of lymphoid follicles, lipid granulomas and plasmacytic satellitosis. The latter is emphasized as a normal phenomenon, may reflect morphologically a physiologic response of the B cell system to antigenic stimulation, and is conspicuously absent in plasmacytic neoplasia. Various secretory forms of plasma cells are illustrated.