Immunological abnormalities in myelodysplastic syndromes. II. Coexistent lymphoid or plasma cell neoplasms: a report of 20 cases unrelated to chemotherapy.

We report a series of 20 patients with the myelodysplastic syndrome (MDS) each with a coexistent lymphoid or plasmacytic neoplasm. In none of the patients did chemotherapy play a part in the pathogenesis. The possible reasons for the coincidence of these conditions are discussed. The frequency and variety of associated neoplasms reinforces the idea that in MDS there are genetically unstable progenitor cells liable to clonal differentiation along a variety of pathways given appropriate stimuli.