Bone marrow neoplastic
Bone marrow - neoplastic myeloid
Myelodysplastic syndromes (MDS)
MDS with ring sideroblasts

Topic Completed: 1 August 2011

Minor changes: 14 August 2020

Copyright: 2002-2020,, Inc.

PubMed Search: MDS with ring sideroblasts[TI]

Nikhil Sangle, M.D.
Page views in 2019: 678
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Cite this page: Sangle N. MDS with ring sideroblasts. website. Accessed September 21st, 2020.
Definition / general
  • Also called idiopathic acquired sideroblastic anemia
  • Ringed sideroblasts detected with iron (Prussian blue) stain represent at least 15% of bone marrow erythroblasts
  • Iron accumulates in mitochondria of erythroid precursors
  • Commonly normochromic macrocytic or normochromic normocytic anemia (hemoglobin usually is < 10 g/dL), usually no other cytopenias but rarely may have thrombocytosis
Case reports
Microscopic (histologic) description
  • Peripheral blood: two RBC populations normal and microcytic hypochromic; occasional coarse basophilic stippling and Pappenheimer bodies; no dysplastic changes, minimal neutropenia, no myeloblasts, no monocytosis, no thrombocytopenia
  • Bone marrow general: hypercellular or normocellular marrow with erythroid hyperplasia
  • Bone marrow erythroid: erythroid hyperplasia, may be mild to moderate dysplasia; markedly increased iron stores, ringed sideroblasts ≥ 15% of marrow erythroblasts, identify with iron stain on marrow smear, has nucleus completely or partially (at least one third circumference) encircled by iron granules
  • Bone marrow myeloid: myeloblasts < 5% (or call RAEB), no dysplasia
  • Bone marrow megakaryocytes: no dysplasia
Microscopic (histologic) images

Images hosted on PathOut server:

Peripheral blood:

Red blood cells are dimorphic
with normochromic and markedly hypochromic cells

Bone marrow smear:

Prussian blue stain shows most red blood cell
precursors are encircled by small granules of iron

Images hosted on other servers:

Bone marrow smear:

RARS with thrombocythemia

Fig 1: peripheral blood shows dual population of microcytic and normocytic red cells with marked poikilocytosis
Fig 2: bone marrow smear shows marked erythroid hyperplasia with many erythroid precursors having megaloblastoid maturation or nucleocytoplasmic asynchrony
Fig 3: iron stain shows numerous ringed sideroblasts (perinuclear iron granules encircle more than 1/3 of nuclear circumference)
Fig 4: transmission EM shows nonspecific siderosomes (black arrow) and iron laden mitochondria (white arrow)

Electron microscopy description
  • Perinuclear iron present in mitochondrial cristae
Electron microscopy images

Images hosted on PathOut server:

Erythroid precursor
shows iron deposits
in mitochondrial cristae

Molecular / cytogenetics description
Differential diagnosis
  • Chloramphenicol or TB drug (isoniazid) exposure, copper deficiency, alcohol or chronic lead poisoning, excess zinc administration
  • Congenital (hereditary x-linked) sideroblastic anemia: causes decrease in the end product of porphyrin synthesis (protoporphyrin IX)
  • Refractory cytopenia with multilineage dysplasia: may have 15% + ringed sideroblasts but also dysplastic changes in 2 or 3 lineages
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