Incidence and characteristics of lymphoid malignancies in untreated myelodysplastic syndromes.

We have analyzed 1,198 patients with untreated myelodysplastic syndromes (MDS) with two main objectives: (1) to determine the prevalence of lymphoid malignancies (LM) in MDS patients; and (2) to ascertain whether there is some relationship between the MDS subtype and the LM type. In fourteen of 1,198 primary MDS patients (1%) (4 with refractory anemia, 3 with refractory anemia with ring sideroblasts, 2 with refractory anemia with excess of blasts and 5 with chronic myelomonocytic leukemia) a LM was detected. In all cases, the LM was of the B-cell type: 6 cases of chronic lymphocytic leukemia, 5 cases of lymphoplasmacytoid lymphoma, and 3 cases of multiple myeloma. B-cell malignancy did not prevail in any MDS subtype and no correlation was observed between the different varieties of both diseases. In conclusion, in this large series, 1% of the untreated patients with MDS had B-cell malignancy, an association that in most cases is likely to be merely coincidental.