Refractory anemia (RA).

• Cytopenia of at least one lineage in the peripheral blood (usually anemia)

• Normal or hypercellular bone marrow with dysplastic changes

• Less than 1 percent blasts in the peripheral blood and less than 5 percent blasts in the bone marrow

Refractory anemia with ringed sideroblasts (RARS)

• Cytopenia (almost always anemia), dysplastic changes, and the same percentages of blood and bone marrow blasts as in refractory anemia

• Ringed sideroblasts accounting for more than 15 percent of all nucleated cells in the bone marrow

Refractory anemia with excess blasts (RAEB)

• Cytopenia of two or more lineages in the peripheral blood

• Dysplastic changes in all three lineages

• Less than 5 percent blasts in the peripheral blood and between 5 and 20 percent blasts in the bone marrow

Chronic myelomonocytic leukaemia (CML)

• Peripheral-blood monocytosis (monocyte count, >1¬10 9 per liter)

• Less than 5 percent blasts in the peripheral blood and up to 20 percent blasts in the bone marrow

Refractory anemia with excess blasts in transformation (RAEB-T)

• Hematologic features similar to those of refractory anemia with excess blasts

• More than 5 percent blasts in the peripheral blood or between 21 and 30 percent blasts in the bone marrow or the presence of Auer rods in the blasts

 

International Prognostic Scoring System for Myelodysplastic Syndromes

 

The overall score is the sum of the scores for bone marrow blasts, karyotype, and cytopenias. The percentage of blasts is scored as follows: <5 percent, 0; 5 to 10 percent, 0.5; 11 to 20 percent, 1.5; and 21 to 30 percent, 2.0. Cytogenetic features associated with a good prognosis (normal karyotype, Y-, 5q-, or 20q-) are scored as 0; those associated with a poor prognosis (abnormal chromosome 7 or three or more abnormalities) are scored as 1.0; and all other cytogenetic abnormalities, which are associated with an intermediate prognosis, are scored as 0.5. A score of 0 is assigned if the patient has no cytopenia or only one type, and a score of 0.5 is assigned if the patient has two or three types of cytopenia. The various types of cytopenia are defined as follows: hemoglobin, <10 g per deciliter; absolute neutrophil count, <1500 per cubic millimeter; and platelet count, <100,000 per cubic millimeter.

References:

1. Heaney ML, Golde DW. Myelodysplasia. N Engl J Med. 1999 May 27;340(21):1649-60. [Medline]

2. Goldman JM. Myeloproliferative and myelodysplastic syndromes: the future. Hematol Oncol Clin North Am. 2003 Oct;17(5):1261-9. [Medline]

3. Greenberg P, Cox C, LeBeau MM, Fenaux P, Morel P, Sanz G, Sanz M, Vallespi T, Hamblin T, Oscier D, Ohyashiki K, Toyama K, Aul C, Mufti G, Bennett J. International scoring system for evaluating prognosis in myelodysplastic syndromes. Blood. 1997 Mar 15;89(6):2079-88. [Medline]