Overview of Classification Systems

Myelodysplastic syndromes (MDS) constitute a complex hematological disorder that gives rise to difficulties in diagnosis and therapeutic decision making.1 Differences in disease presentation, progression, and outcome have made it necessary to use classification and prognostic systems to improve diagnosis, prognostication, treatment selection, and therapy monitoring.1

MDS classification and staging systems are key for an accurate diagnosis and selection of therapy, based on1,2:

  • Peripheral blood and bone marrow (BM) morphology
  • BM biopsy
  • Cytogenetics

Classification systems in MDS have evolved over time

Since the original classification system, referred to as French-American-British (FAB), was established in 1982, advances in science have allowed for refinement of the key criteria and improved accuracy.3-5 The World Health Organization (WHO) 2016 revision is currently the global standard.6


BM, bone marrow; FAB, French-American-British; WHO, World Health Organization.

References: 1. Invernizzi R, Filocco A. Myelodysplastic syndrome: classification and prognostic systems. Oncol Rev. 2010;4(1):25-33. 2. Malcovati L, Della Porta MG, Ambaglio I, et al. Impact of the degree of anemia on the outcome of patients with myelodysplastic syndrome and its integration into the WHO classification-based Prognostic Scoring System (WPSS). Haematologica. 2011;96(6):1433-1440. 3. Bennett JM, Catovsky D, Daniel MT, et al. Proposals for the classification of the myelodysplastic syndromes. Br J Haematol. 1982;51(2):189-199. 4. Harris NL, Jaffe ES, Diebold J, et al. World Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues: report of the Clinical Advisory Committee meeting—Airlie House, Virginia, November 1997. J Clin Oncol. 1999;17(12):3835-3849. 5. Vardiman JW, Thiele J, Arber DA, et al. The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes. Blood. 2009;114(5):937-951. 6. Arber DA, Orazi A, Hasserjian R, et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016;127(20):2391-2405.