Refractory cytopenias with unilineage dysplasia (RCUD) is a frequent low-risk subtype of myelodysplastic syndrome (MDS; see this term) characterized by refractory cytopenias associated with dysplasia limited to one cell lineage.

Inflammatory changes in the synovial membranes and articular structures with widespread fibrinoid degeneration of the collagen fibers in mesenchymal tissues, as well as atrophy and rarefaction of bony structures.