Abnormal ("Ringed") Sideroblasts in Various Hematologic and Non-Hematologic Disorders

Seventy-six patients with various hematologie and nonhematologic conditions were studied to determine the incidence of sideroblasts containing excessive numbers of Prussian-blue positive granules arranged in a ring around the nucleus. Large numbers of these cells were found in "refractory, normoblastic anemia," a condition characterized by ineffective erythropoiesis, and in certain infections. They also could be produced by nitrogen mustard. Aside from this, they were found in small to moderate numbers in a wide variety of conditions, and no conclusions could be drawn.