The new WHO nomenclature: introduction and myeloid neoplasms.

1. Bernadette F Rodak, MS CLSpH(NCA)[⇑][1] 1. is Associate Professor of Clinical Laboratory Science, Indiana University, Indianapolis IN 2. Susan J Leclair, PhD CLS(NCA) 1. is Professor of Medical Laboratory Science at University of Massachusetts Dartmouth, Dartmouth MA 1. Address for correspondence: Bernadette F Rodak MS CLSpH(NCA), Clinical Laboratory Science Program, Indiana University, 1120 South Drive; Fesler 409, Indianapolis IN 46202-5113. (317) 274-1267, (317) 278-0643 (fax). brodak{at}iupui.edu 1. Compare and contrast the principles of FAB and WHO classifications for myeloid neoplasms. 2. Categorize presentations into the WHO nomenclature. 3. Justify the percentage of blasts necessary for a diagnosis of acute leukemia in the WHO system. 4. Explain the four parameters on which the WHO classification is based. 5. Describe multi-lineage dysplasia and give examples of peripheral blood and bone marrow characteristics. 6. Summarize the four categories of acute myeloid leukemia in the WHO system. 7. Associate recurrent genetic abnormalities with specific leukemic presentations. 8. Associate therapy related leukemia and myelodysplastic syndromes with chemotherapeutic agents. 9. Describe the entities included in AML, not otherwise categorized. 10. Summarize the five categories of myelodysplastic syndromes included in the WHO classification. 11. Rationalize the creation of the category of MPD/MDS and discuss the disorders included in that category. Historically, diseases in the form of a single patient were identified and described by a single physician. Because only rarely did two or more physicians see the same type of patient in the same time frame, the classification of most diseases is not as complex as it might otherwise be. Blood cells, on the other hand, were described and named by many different people in many countries many times over. As individuals saw and described cells, they gave them names, and assigned those cells to specific groups with little to no clear understanding of the reality of the cells. To further confuse classification schema were the inherent difficulties in 18th and 19th century lens technology and, until the utilization of the Romanowsky-based stains, the lack of common staining methods. The result of this early work was the sometimes contradictory cellular nomenclature. This lack of clarity was reflected in the nomenclature of various malignant hematopoietic diseases such as the leukemias. While there was some concern over this lack of clarity, the treatment of the various hematologic malignancies was such that a more definitive schema was not required. However, in 1946, a landmark article reported the first successful treatment of malignancy by chemical means.1 This work required that naming schema be consistent if one were to utilize the appropriate therapy for these diseases. The first step was to determine the identity of the various cell forms. Once the nomenclature of individual cells was agreed upon, it was the logical next step to… ABBREVIATIONS: ACML = atypical CML; AML = acute myelogenous leukemia; APL = acute promyelocytic leukemia; CIMF = chronic idiopathic myelofibrosis; CLL = chronic lymphocytic leukemia; CML = chronic myelogenous leukemia; CMML = chronic myelomonocytic leukemia; CNL = chronic neutrophilic leukemia; DIC = disseminated intravascular coagulation; FAB = French-American-British; JMML = juvenile chronic myelomonocytic leukemia; MDS = myelodysplastic syndromes; MPD = myeloproliferative diseases; REAL = Revised European-American Classification of Lymphoid Neoplasms; RA = refractory anemia; RAEB = refractory anemia with excess blasts; RARS = refractory anemia with ringed sideroblasts; RCMD = refractory cytopenia with multilineage dysplasia; WHO = World Health Organization. 1. Compare and contrast the principles of FAB and WHO classifications for myeloid neoplasms. 2. Categorize presentations into the WHO nomenclature. 3. Justify the percentage of blasts necessary for a diagnosis of acute leukemia in the WHO system. 4. Explain the four parameters on which the WHO classification is based. 5. Describe multi-lineage dysplasia and give examples of peripheral blood and bone marrow characteristics. 6. Summarize the four categories of acute myeloid leukemia in the WHO system. 7. Associate recurrent genetic abnormalities with specific leukemic presentations. 8. Associate therapy related leukemia and myelodysplastic syndromes with chemotherapeutic agents. 9. Describe the entities included in AML, not otherwise categorized. 10. Summarize the five categories of myelodysplastic syndromes included in the WHO classification. 11. Rationalize the creation of the category of MPD/MDS and discuss the disorders included in that category. [1]: #corresp-1