Sideroblast seen in-

Sideroblasts are nucleated erythroblasts with granules of iron accumulated in mitochondria surrounding nucleus.Ring sideroblasts, iron laden mitochondria form 1/3rd or more of nucleus are seen in myelofibrosis.In thalassemia, microcytic hypochromic anisopoikilocytosis are seen .In alcoholism,there is folate deficiency as ethanol inhibits absorption of folate.In iron overload,absence of hepcidin leads to hyperabsorption of iron Ref. Hoffbrand hematology,6th, pg: 47. Robbins and Cotran Pathologic basis of disease,pg:640]