Ring Sideroblasts

Abnormal nucleated RBCs with granules of iron accumulated in perinuclear mitochondria, which can be seen by microscopy after special iron stains such as Prussian Blue. Increased ringed sideroblasts are a diagnostic feature of certain disease states such as the Myelodysplastic syndrome Refractory Anemia with Ring Sideroblasts. Other causes of ringed sideroblasts include copper deficiency, and zinc toxicity (which could induce copper deficiency). Ring sideroblasts are specifically defined as sideroblasts encircled by 5 or more iron granules and.surrounding at least 1/3 of the nucleus (hence the term " Ring Sideroblasts").