Concurrent development of preleukaemic, lymphoproliferative and plasma cell disorders

Summary. A patient is described who presented with a combined preleukaemic, lymphoproliferative and plasma cell disorder. These disorders were not related to cytotoxic therapy. The clonal nature of the lymphoid component was demonstrated by lymphocyte surface marker studies and the clonal nature of the plasma cell component by immunoperoxidase studies. Since the involved lymphoid and plasma cells contained different heavy and light chains, they were felt to originate from two separate B cell clones not related to the clone responsible for the preleukaemic component.