Intramedullary erythrophagocytosis in myelodysplastic syndrome with heterozygous U2AF1 Q157R variant

This report highlights a somewhat unique case of U2AF1 mutated myelodysplastic syndrome (MDS) with morphological evidence of increased intramedullary erythrophagocytosis, in the absence of obvious clinical signs of hemolysis. These findings merit investigation in a larger cohort of U2AF1 mutated MDS cases to further delineate the morphological spectrum of ineffective intramedullary hematopoiesis and nonimmune hemolysis, including features distinctive to S34 and Q157 variants.