Chronic Myeloid Neoplasms
Myelodysplastic syndromes
Refractory anemia

Author: Nikhil Sangle, M.D. (see Authors page)

Revised: 1 March 2017, last major update August 2011

Copyright: (c) 2002-2017,, Inc.

PubMed Search: Refractory anemia [title] Myeloid Neoplasms

Cite this page: Refractory anemia. website. Accessed June 22nd, 2018.
Definition / general
  • Also called Refractory cytopenia with unilineage dysplasia
  • Ineffective erythropoiesis with erythroid hyperplasia of marrow but low reticulocyte count and anemia
  • Initially termed "refractory" because refractory to iron, folate and vitamin B12 supplements
  • Diagnosis of exclusion; must eliminate other possible causes of anemia (folate / B12 deficiency, drugs, toxins, arsenic, congenital dyserythropoietic anemia)
  • 90 - 95% of patients have a low or intermediate International prognostic scoring system score
  • Occasionally evolves to more aggressive MDS or AML
  • Anemia (Hb < 10g/dL), usually no other cytopenias
  • None or transfusion support
  • Combination of all trans retinoic acid, calcitriol and androgens may be effective (Leuk Res 2006;30:935)
Microscopic (histologic) description
  • Peripheral blood: anisocytosis (variation in size), poikilocytosis (variation in shape), normochromic oval macrocytes; usually no neutrophilic or platelet dysplasia; no / rare myeloblasts, monocytes are less than 1 billion/L
  • Bone marrow: hypercellular or normocellular
  • Erythroid: erythroid hyperplasia, may have mild to moderate dysplasia with megaloblastoid features; < 15% ringed sideroblasts
  • Myeloid: myeloblasts < 5% (or call RAEB), no / slight dysplasia
  • Megakaryocytes: no / slight dysplasia
  • Patients with 2 - 4% blasts in peripheral blood and < 5% blasts in bone marrow should be classified as RAEB-1
Microscopic (histologic) images

Images hosted on PathOut server:

Bone marrow biopsy:

Slightly hypercellular for a 53 year old man,
marked erythroid hyperplasia,
prominent megakaryocytes but no increase in their number

Bone marrow smear:

Two postmitotic erythroid precursors
(upper left) with internuclear chromatin bridging

Molecular / cytogenetics description
  • No specific abnormality, 70% have normal karyotype (Atlas of Genetics and Cytogenetics)
  • Refractory neutropenia and refractory thrombocytopenia are rare and caution needs to be exercised in making these diagnoses (these fall into the category of Refractory cytopenia with unilineage dysplasia)