Concurrent myelodysplastic malignancies and plasma cell neoplasms; a clinicopathological study with prognostic implications.

Plasma cell neoplasms (PCN) have infrequently been reported in patients with myelodysplastic syndrome (MDS) and even more rarely in those with myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN). We report the clinicopathologic features of 26 patients with bone marrow myelodysplasia accompanied by PCN, including 21 patients with MDS and 5 with MDS/MPN. The clinicopathologic features of the MDS/MPN-PCN were compared to those of the MDS-PCN group and 68 cases of MDS/MPN without PCN, respectively. The MDS/MPN-PCN group was notable for increased reticulin fibrosis > grade 1 when compared to both the MDS/MPN (p = 0.007) and MDS-PCN (p = 0.02) groups. MDS/MPN-PCN was associated with worse overall survival when compared with MDS-PCN (p = 0.03) and but not with MDS/MPN. Notably, hemoglobin level <8 g/dl (p = 0.008), and IDH2 somatic mutation (p = 0.003) were independent predictors of poor overall survival in all patients with MDS/MPN. Analysis of larger cohorts is required to confirm these associations and provide an insight into the pathogenesis.