Epidemiology

• Classified as a Chronic Myeloproliferative Disease (see Chronic Myeloproliferative Diseases, Chronic Myeloproliferative Diseases)

---

Etiology

• xxx

---

Physiology

• xxx

---

Diagnosis

• xxx

---

WHO Classification of Myelodysplastic Syndromes [MEDLINE]

Refractory Anemia (RA)

• Blood Findings
  • Anemia (see Anemia, Anemia)
  • No or rare blasts
• Bone Marrow Findings
  • Eythroid Dysplasia Alone
  • <5% Blasts
  • <15% Ringed Sideroblasts

Refractory Cytopenia with Unilineage Dysplasia

• Epidemiology: accounts for <5% of myelodysplastic syndrome cases
• Blood Findings: one of the following
  • Refractory Anemia (see Anemia, Anemia)
  • Refractory Neutropenia
  • Refractory Thrombocytopenia
• Bone Marrow Findings
  • xxx

Refractory Anemia with Ringed Sideroblasts (RARS)

• Epidemiology: accounts for <5% of myelodysplastic syndrome cases
• Blood Findings
  • Anemia (see Anemia, Anemia)
  • No Blasts
• Bone Marrow Findings
  • Erythroid dysplasia alone
  • < 5% blasts
  • ≥ 15% ringed sideroblasts

Refractory Cytopenia with Multilineage Dysplasia (RCMD)

• Epidemiology: accounts for 70% of myelodysplastic syndrome cases
• Blood Findings
  • Cytopenias (bicytopenia or pancytopenia)
  • no or rare blasts
  • no Auer rods
  • < 1 billion monocytes per liter
• Bone Marrow Findings
  • Dysplasia in ≥ 10% of cells in ≥ 2 myeloid cell lines
  • < 5% blasts
  • No Auer rods
  • <15% ringed sideroblasts

Refractory Cytopenia with Multilineage Dysplasia and Ringed Sideroblasts

• Epidemiology: accounts for 70% of myelodysplastic syndrome cases
• Blood Findings
  • Cytopenias (bicytopenia or pancytopenia)
  • No or rare blasts
  • No Auer rods,
  • < 1 billion monocytes per liter
• Bone Marrow Findings
  • Dysplasia in ≥ 10% of cells in ≥ 2 myeloid cell lines
  • < 5% blasts
  • No Auer rods
  • ≥ 15% ringed sideroblastsxx

Refractory Anemia with Excess Blasts-1 (RAEB-1)

• Epidemiology: accounts for 25% of myelodysplastic syndrome cases
• Blood Findings
  • Cytopenias
  • < 5% blasts
  • No Auer rods
  • <1 billion monocytes per liter
• Bone Marrow Findings
  • Unilineage or multilineage dysplasia
  • 5—9% blasts
  • No Auer rods

Refractory Anemia with Excess Blasts-2 (RAEB-2)

• Epidemiology: accounts for 25% of myelodysplastic syndrome cases
• Blood Findings
  • Cytopenias
  • 5—19% blasts
  • Occasional Auer rods
    < 1 billion monocytes per liter
• Bone Marrow Findings
  • Unilineage or multilineage dysplasia
  • 10—19% blasts
  • Occasional Auer rods

Myelodysplastic Syndrome with Isolated del(5q)

• Epidemiology: accounts for 5% of myelodysplastic syndrome cases
• Blood Findings
  • Anemia (see Anemia, Anemia)
  • <5% Blasts
  • Platelet count normal to increased
• Bone Marrow Findings
  • Normal-to-increased megakaryocytes with hypolobated nuclei
  • < 5% blasts
  • No Auer rods
  • Isolated del (5 q)

Myelodysplastic Syndrome, Unclassified (MDS-U)

• Epidemiology: accounts for <5% of myelodysplastic syndrome cases
• Blood Findings
  • Cytopenias
  • No or rare blasts
  • No Auer rods
• Bone Marrow Findings
  • Unilineage dysplasia in granulocytes or megakaryocytes
  • <5% blasts
  • No Auer rodsx

---

Clinical Manifestations

Pulmonary Manifestations

• Pulmonary Hypertension (see Pulmonary Hypertension, Pulmonary Hypertension)
  • Early Chest Series of Unexplained Pulmonary Hypertension in Myeloproliferative Disorders (2001) [MEDLINE]: 14/26 patients had platelet counts >600k
    • 12 patients had diagnosis of myeloid metaplasia with myelofibrosis
    • 5 patients had diagnosis of essential thrombocytosis
    • 6 patients had diagnosis of polycythemia vera
    • 2 patients had diagnosis of myelodysplastic sydrome
• xxx
• xxx
• xxx
• xxx

Other Manifestations

• xxx
• xxx
• xxx
• xxx

---

Treatment

• xxx

---

References

• Unexplained pulmonary hypertension in chronic myeloproliferative disorders. Chest. 2001 Sep;120(3):801-8 [MEDLINE]
• The World Health Organization (WHO) classification of the myeloid neoplasms. Blood. 2002 Oct 1;100(7):2292-302 [MEDLINE]
• Incidence of pulmonary hypertension in patients with chronic myeloproliferative disorders. Haematologica 2004;89:245—7 [MEDLINE]
• Pulmonary hypertension in patients with chronic myeloproliferative disorders. Eur Respir J. 2010 Jun;35(6):1396-406. doi: 10.1183/09031936.00175909 [MEDLINE]
• Non-infectious pulmonary complications of myelodysplastic syndromes and chronic myeloproliferative disorders. Rev Mal Respir. 2011 Jun;28(6):e18-27. doi: 10.1016/j.rmr.2009.04.001. Epub 2011 Jun 8[MEDLINE]