The revised 4th edition of the World Health Organization (WHO4R) classification lists myelodysplastic syndromes with ring sideroblasts (MDS-RS) as a separate entity with single lineage (SLD) or multilineage (MLD) dysplasia. On the other hand, the International Consensus Classification (ICC) distinguishes between MDS with SF3B1 mutation (MDS-SF3B1) and MDS-RS without SF3B1 mutation. A new study from the Mayo Clinic analyzes 170 patients with WHO4R-defined MDS-RS and shows a significant difference in overall survival between MDS-RS-MLD and MDS-RS-SLD but not between MDS-RS with and without SF3B1 mutation, concluding that the MLD-based, as opposed to the SF3B1 mutation-based, disease classification for MDS-RS is prognostically more relevant.

Light chain cast nephropathy (LCCN) is a well described multiple myeloma (MM)-defining event and correlates with poorer outcome. The new study by Martins and colleagues analyzes features of LCCN in non-MM mature B-cell neoplasms and compares its presentation with that of MM-associated LCCN. Results show that patients with LCCN associated with B-cell neoplasms have similar presentation and outcome to those with MM-associated LCCN, thus emphasizing the need for a close and longitudinal assessment of kidney function in patients with mature B-cell neoplasms with plasmacytic differentiation.