Pediatric Myelodysplasia Workup
- Author: Natalia Dixon, MD; Chief Editor: Robert J Arceci, MD, PhD more...
Laboratory Studies
CBC count (differential and peripheral blood smear)
Peripheral blood count reveals anemia, neutropenia, and/or thrombocytopenia. The anemia is often macrocytic. Cytopenias can evolve and progress over a period of weeks to months.
The blood smear commonly reveals macrocytosis, hypogranular granulocytes, pseudo–Pelger-Huet anomaly (hypogranular and hypolobulated granulocytes), and giant platelets. Reticulocyte counts are low despite normal numbers of erythroid progenitors in the marrow. In JMML, marked monocytosis may be present.
Bone marrow aspirate and trephine core biopsy
See Procedures and Histologic Findings.
Quantitative hemoglobin electrophoresis
This may reveal elevated hemoglobin F levels, indicating reversion to fetal erythropoiesis due to bone marrow stress.
Cytogenetic studies (conventional karyotype, fluorescence in situ hybridization (FISH), polymerase chain reaction)
These studies reveal chromosomal abnormalities in 40-70% of pediatric cases of myelodysplasia syndrome (MDS).
Acquired chromosome abnormalities confirm the diagnosis when myelodysplasia syndrome is suspected.
The most commonly known abnormalities include monosomy 7 or 7q, monosomy 5 or 5q, or trisomy 8. myelodysplasia syndrome may also be associated with 20q, isochromosome 17, and abnormalities of 11q. Reciprocal translocations and inversions are uncommon.
Children who present with a peripheral blood and/or bone marrow disorder associated with t(8;21)(q22;q22), inv(16)(p13.1q22) or t(16;16)(p13.1;q22) or t(15;17)(q22;q12) should be considered to have AML regardless of the blast count.[4]
Fanconi anemia test
A Fanconi screen using diepoxybutane (DEB) or mitomycin C stimulation reveals abnormal chromosome breakage if this syndrome is present.
Paroxysmal nocturnal hemoglobinuria (PNH) test
Measurement of 2 complement regulatory proteins, CD55 (decay accelerating factor [DAF]) and CD59 (membrane inhibitor of reactive lysis [MIRL]) aids in diagnosis of PNH. The clinical picture of PNH is rare in childhood, although PNH clones in the absence of hemolysis or thrombosis may be observed in children with refractory cytopenia of childhood (RCC).
Human leukocyte antigen (HLA) typing
Human leukocyte antigen (HLA) typing of patient and family members should be performed at the outset, in anticipation of allogeneic hematopoietic stem cell transplantation (HSCT).
Additional laboratory studies
In most cases, myelodysplasia syndrome is diagnosed after a history and physical examination, followed by the laboratory workup described above. In some instances, additional tests may be warranted.
Viral serologies, especially human immunodeficiency virus (HIV), cytomegalovirus (CMV), EBV, and parvovirus, can be used to exclude viral etiologies of altered hematopoiesis.
The novo or primary form of myelodysplasia syndrome in children should be distinguished from cases of secondary myelodysplasia syndrome that follow congenital or acquired bone marrow failure syndromes[23] and from therapy-related myelodysplasia syndrome that follows cytotoxic therapy for a previous neoplastic or nonneoplastic condition.
Imaging Studies
Imaging studies do not contribute to establishing the diagnosis or prognosis of myelodysplasia syndrome.
Procedures
Bone marrow aspiration and biopsy are essential to establish the diagnosis and to classify the myelodysplasia syndrome.
Biopsy findings are needed to ascertain cellular architecture, cellularity, percentage of blasts, and the presence of fibrosis.
Bone marrow findings are reviewed under Histologic Findings.
As myelodysplasia has a varied temporal course, these procedures may need to be repeated at different time points if initial studies are not confirmatory and there is no alternate explanation for clinical/laboratory findings.
Histologic Findings
Bone marrow aspiration and biopsy are essential diagnostic tools. The minimal morphologic criteria for the diagnosis of myelodysplasia syndrome remains similar in the most recent WHO classification system: In the appropriate clinical setting, at least 10% of the cells of at least 1 myeloid bone marrow lineage (erythroid, granulocytic, megaryocytic) must show unequivocal dysplasia for the lineage to be considered dysplastic.[4] Bone marrow biopsy should also be performed to assess cellularity and architecture because fibrosis can be a component of disease. The bone marrow of patients with myelodysplasia syndrome can be normocellular or hypocellular.[24] Hypocellularity of the bone marrow is more commonly observed in childhood myelodysplasia syndrome than in older patients.
Because the diagnosis of myelodysplasia syndrome relies heavily on marrow morphology, interobserver and intraobserver differences complicate disease classification. The FAB system, defined by a consensus of hematologists and hematopathologists, should be used in characterizing marrow results. The current FAB system is strictly based on morphology and does not take into account cytogenetics or predisposing abnormalities, which limits its use in children.[25] The changing classification schemes and continuing controversies underscore the fact that the understanding of myelodysplasia is evolving.[26, 27, 28]
As noted previously, the WHO classification system published in 2008 devotes a section to childhood myelodysplasia syndrome; a provisional entity, refractory cytopenia of childhood (RCC) is introduced in the classification for the first time. The category of RCC is reserved for childhood cases with less than 2% blasts in peripheral blood and less than 5% blasts in the bone marrow and persistent cytopenias associated with dysplasia in at least 2 cell lineages.[4, 29]
The morphological findings of RCC are illustrated in the following table.[4]
Morphological findings of refractory cytopenia of childhood. Children with myelodysplasia syndrome and 2-19% blasts in peripheral blood and/or 5-19% blasts in the bone marrow are categorized using the same criteria as adults with myelodysplasia syndrome.[29] In contrast to adults, isolated refractory anemia is uncommon in children with myelodysplasia syndrome, who more commonly present with thrombocytopenia and/or neutropenia, often accompanied by a hypocellular bone marrow.[27]
The WHO classification includes some cytogenetic information; the most recently proposed WHO classification scheme for myelodysplasia syndrome is as follows:[4]
- Refractory cytopenia with unilineage dysplasia - Refractory anemia, refractory neutropenia, refractory thrombocytopenia
- Refractory anemia with ringed sideroblasts
- Refractory anemia with multiple dysplasia
- Refractory anemia with excess blasts
- Myelodysplastic syndrome with isolated del(5q)
- Myelodysplastic syndrome, unclassifiable
- Childhood myelodysplastic syndrome - Provisional entity: Refractory cytopenia of childhood (RCC)
JMML is unique to the pediatric age group and hence categorized separately from myelodysplasia syndrome. This disease is characterized by the absence of t(9;22), an absolute peripheral monocyte count of higher than 450/mcL, elevated hemoglobin F levels, selective in vitro hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF), and excessive proliferation of monocyte-macrophage colonies in clonogenic culture. In JMML, nearly 75% of patients demonstrate mutually exclusive mutations of PTPN11, NRAS or KRAS, or NF1, all of which encode signaling proteins in RAS-dependent pathways.
Diagnostic Challenges
Diagnostic problems arise when the clinical or laboratory findings suggest myelodysplasia syndrome but the morphologic findings are inconclusive; when secondary dysplasia is caused by nutritional deficiencies, medications, toxins, growth factor therapy, inflammation, or infection or when bone marrow hypocellularity or myelofibrosis obscures the underlying disease process.[30]
Per the most recent WHO classification system, if myelodysplasia syndrome has inconclusive morphologic features, a presumptive diagnosis of myelodysplasia syndrome can be made if a specific clonal abnormality is present. However, the list[4] is not fully inclusive (not included, but significant if found: del(20), trisomy 8 and –Y). These abnormalities, reported in some adult patients with aplastic anemia or other cytopenias are associated with favorable response to immunosuppressive therapy.[31] This emphasizes the variation in temporal evolution of the disease and should be kept in mind for clinical decision making.
Hypocellular myelodysplasia syndrome may be more common in children because of the relative prevalence of inherited marrow failure syndromes. Hence, if no MDS-related cytogenetic abnormalities are present, the distinction between childhood MDS and evolving aplastic anemia or congenital bone marrow failure syndrome can be very difficult. Therefore, at least 2 biopsies obtained at least 2 weeks apart are recommended to facilitate the detection of representative bone marrow spaces containing foci of erythropoiesis.[4]
The morphological changes in the bone marrow of children with hypoplastic RCC are compared with those with aplastic anemia in table 2.[4]
Morphological findings of hypoplastic refractory cytopenia of childhood and aplastic anemia of childhood. Barlogie B, Johnston DA, Keating M, et al. Evolution of oligoleukemia. Cancer. May 15 1984;53(10):2115-24. [Medline].
Jaffe ES, Harris NL, Stein H, et al, eds. World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of Haematopoietic and Lymphoid Tissues. 3rd ed. International Agency for Research on Cancer (IARC); 2001.
Bennett JM, Catovsky D, Daniel MT, Flandrin G, Galton DA, Gralnick HR, et al. Proposals for the classification of the myelodysplastic syndromes. Br J Haematol. Jun 1982;51(2):189-99. [Medline].
Swerdlow SH, Campo E, Harris NL, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. 4th ed. Lyon, France: International Agency for Research on Cancer (IARC); 2008.
Tefferi A, Vardiman JW. Myelodysplastic syndromes. N Engl J Med. Nov 5 2009;361(19):1872-85. [Medline].
Owen C, Barnett M, Fitzgibbon J. Familial myelodysplasia and acute myeloid leukaemia--a review. Br J Haematol. Jan 2008;140(2):123-32. [Medline].
Kalra R, Paderanga DC, Olson K, Shannon KM. Genetic analysis is consistent with the hypothesis that NF1 limits myeloid cell growth through p21ras. Blood. Nov 15 1994;84(10):3435-9. [Medline].
Shannon KM, O'Connell P, Martin GA, Paderanga D, Olson K, Dinndorf P, et al. Loss of the normal NF1 allele from the bone marrow of children with type 1 neurofibromatosis and malignant myeloid disorders. N Engl J Med. Mar 3 1994;330(9):597-601. [Medline].
Ortmann CA, Niemeyer CM, Wawer A, Ebell W, Baumann I, Kratz CP. TERC mutations in children with refractory cytopenia. Haematologica. May 2006;91(5):707-8. [Medline].
Marrone A, Sokhal P, Walne A, Beswick R, Kirwan M, Killick S, et al. Functional characterization of novel telomerase RNA (TERC) mutations in patients with diverse clinical and pathological presentations. Haematologica. Aug 2007;92(8):1013-20. [Medline].
Vidal DO, Paixao VA, Brait M, et al. Aberrant methylation in pediatric myelodysplastic syndrome. Leuk Res. Feb 2007;31(2):175-81. [Medline].
Hasle H, Kerndrup G, Jacobsen BB. Childhood myelodysplastic syndrome in Denmark: incidence and predisposing conditions. Leukemia. Sep 1995;9(9):1569-72. [Medline].
Emanuel PD. Myelodysplasia and myeloproliferative disorders in childhood: an update. Br J Haematol. Jun 1999;105(4):852-63. [Medline].
Hasle H, Jacobsen BB, Pedersen NT. Myelodysplastic syndromes in childhood: a population based study of nine cases. Br J Haematol. Aug 1992;81(4):495-8. [Medline].
Passmore SJ, Chessells JM, Kempski H, Hann IM, Brownbill PA, Stiller CA. Paediatric myelodysplastic syndromes and juvenile myelomonocytic leukaemia in the UK: a population-based study of incidence and survival. Br J Haematol. Jun 2003;121(5):758-67. [Medline].
Pui CH, Schrappe M, Ribeiro RC, Niemeyer CM. Childhood and adolescent lymphoid and myeloid leukemia. Hematology Am Soc Hematol Educ Program. 2004;118-45. [Medline].
Aul C, Gattermann N, Schneider W. Age-related incidence and other epidemiological aspects of myelodysplastic syndromes. Br J Haematol. Oct 1992;82(2):358-67. [Medline].
Arico M, Biondi A, Pui CH. Juvenile myelomonocytic leukemia. Blood. Jul 15 1997;90(2):479-88. [Medline].
Kardos G, Baumann I, Passmore SJ, Locatelli F, Hasle H, Schultz KR. Refractory anemia in childhood: a retrospective analysis of 67 patients with particular reference to monosomy 7. Blood. Sep 15 2003;102(6):1997-2003. [Medline].
Bhatia S, Krailo MD, Chen Z, Burden L, Askin FB, Dickman PS, et al. Therapy-related myelodysplasia and acute myeloid leukemia after Ewing sarcoma and primitive neuroectodermal tumor of bone: A report from the Children's Oncology Group. Blood. 2007;109(1):46-51.
Hasle H. Myelodysplastic and myeloproliferative disorders in children. Curr Opin Pediatr. Feb 2007;19(1):1-8. [Medline].
Barnard DR, Woods WG. Treatment-related myelodysplastic syndrome/acute myeloid leukemia in survivors of childhood cancer--an update. Leuk Lymphoma. May 2005;46(5):651-63. [Medline].
Teo JT, Klaassen R, Fernandez CV, Yanofsky R, Wu J, Champagne J. Clinical and genetic analysis of unclassifiable inherited bone marrow failure syndromes. Pediatrics. Jul 2008;122(1):e139-48. [Medline].
Auletta JJ, Shurin S. Improved hematopoiesis using amifostine in secondary myelodysplasia. J Pediatr Hematol Oncol. Nov-Dec 1999;21(6):531-4. [Medline].
Bader-Meunier B, Mielot F, Tchernia G, et al. Myelodysplastic syndromes in childhood: report of 49 patients from a French multicentre study. French Society of Paediatric Haematology and Immunology. Br J Haematol. Feb 1996;92(2):344-50. [Medline].
Mandel K, Dror Y, Poon A, Freedman MH. A practical, comprehensive classification for pediatric myelodysplastic syndromes: the CCC system. J Pediatr Hematol Oncol. Oct 2002;24(7):596-605. [Medline].
Hasle H, Niemeyer CM, Chessells JM, Baumann I, Bennett JM, Kerndrup G. A pediatric approach to the WHO classification of myelodysplastic and myeloproliferative diseases. Leukemia. Feb 2003;17(2):277-82. [Medline].
Occhipinti E, Correa H, Yu L, Craver R. Comparison of two new classifications for pediatric myelodysplastic and myeloproliferative disorders. Pediatr Blood Cancer. Mar 2005;44(3):240-4. [Medline].
Vardiman JW, Thiele J, Arber DA, Brunning RD, Borowitz MJ, Porwit A. The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes. Blood. Jul 30 2009;114(5):937-51. [Medline].
Vardiman JW. Hematopathological concepts and controversies in the diagnosis and classification of myelodysplastic syndromes. Hematology Am Soc Hematol Educ Program. 2006;199-204. [Medline].
Gupta V, Brooker C, Tooze JA, Yi QL, Sage D, Turner D. Clinical relevance of cytogenetic abnormalities at diagnosis of acquired aplastic anaemia in adults. Br J Haematol. Jul 2006;134(1):95-9. [Medline].
Bierings M, Nachman JB, Zwaan CM. Stem cell transplantation in pediatric leukemia and myelodysplasia: state of the art and current challenges. Curr Stem Cell Res Ther. Jan 2007;2(1):53-63. [Medline].
Bunin N, Saunders F, Leahey A, et al. Alternative donor bone marrow transplantation for children with juvenile myelomonocytic leukemia. J Pediatr Hematol Oncol. Nov-Dec 1999;21(6):479-85. [Medline].
Kalwak K, Wojcik D, Gorczynska E, et al. Allogeneic hematopoietic cell transplantation from alternative donors in children with myelodysplastic syndrome: is that an alternative?. Transplant Proc. Jun 2004;36(5):1574-7. [Medline].
Mantadakis E, Shannon KM, Singer DA, Finklestein J, Chan KW, Hilden JM. Transient monosomy 7: a case series in children and review of the literature. Cancer. Jun 15 1999;85(12):2655-61. [Medline].
Barnard DR, Alonzo TA, Gerbing RB, Lange B, Woods WG. Comparison of childhood myelodysplastic syndrome, AML FAB M6 or M7, CCG 2891: report from the Children's Oncology Group. Pediatr Blood Cancer. Jul 2007;49(1):17-22. [Medline].
Bennett JM. Classification of the myelodysplastic syndromes. Clin Haematol. Nov 1986;15(4):909-23. [Medline].
Boogaerts MA, Nelissen V, Roelant C, Goossens W. Blood neutrophil function in primary myelodysplastic syndromes. Br J Haematol. Oct 1983;55(2):217-27. [Medline].
Cheson BD, Greenberg PL, Bennett JM, et al. Clinical application and proposal for modification of the International Working Group (IWG) response criteria in myelodysplasia. Blood. Jul 15 2006;108(2):419-25. [Medline].
Clark R, Peters S, Hoy T, et al. Prognostic importance of hypodiploid hemopoietic precursors in myelodysplastic syndromes. N Engl J Med. Jun 5 1986;314(23):1472-5. [Medline].
De Witte T, Van Biezen A, Hermans J, et al. Autologous bone marrow transplantation for patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia following MDS. Chronic and Acute Leukemia Working Parties of the European Group for Blood and Marrow Transplantation. Blood. Nov 15 1997;90(10):3853-7. [Medline]. [Full Text].
Dewald GW, Pierre RV, Phyliky RL. Three patients with structurally abnormal X chromosomes, each with Xq13 breakpoints and a history of idiopathic acquired sideroblastic anemia. Blood. Jan 1982;59(1):100-5. [Medline].
Fohlmeister I, Fischer R, Mödder B, Rister M, Schaefer HE. Aplastic anaemia and the hypocellular myelodysplastic syndrome: histomorphological, diagnostic, and prognostic features. J Clin Pathol. Nov 1985;38(11):1218-24. [Medline]. [Full Text].
Freedman MH, Bonilla MA, Fier C, et al. Myelodysplasia syndrome and acute myeloid leukemia in patients with congenital neutropenia receiving G-CSF therapy. Blood. Jul 15 2000;96(2):429-36. [Medline]. [Full Text].
Golde DW. The stem cell. Sci Am. Dec 1991;265(6):86-93. [Medline].
Hasegawa D, Manabe A, Kubota T, et al. Methylation status of the p15 and p16 genes in paediatric myelodysplastic syndrome and juvenile myelomonocytic leukaemia. Br J Haematol. Mar 2005;128(6):805-12. [Medline].
Hasle H, Arico M, Basso G, et al. Myelodysplastic syndrome, juvenile myelomonocytic leukemia, and acute myeloid leukemia associated with complete or partial monosomy 7. European Working Group on MDS in Childhood (EWOG-MDS). Leukemia. Mar 1999;13(3):376-85. [Medline].
Hasle H, Baumann I, Bergstrasser E, et al. The International Prognostic Scoring System (IPSS) for childhood myelodysplastic syndrome (MDS) and juvenile myelomonocytic leukemia (JMML). Leukemia. Dec 2004;18(12):2008-14. [Medline].
Heaney ML, Golde DW. Myelodysplasia. N Engl J Med. May 27 1999;340(21):1649-60. [Medline].
Hofmann WK, Ottmann OG, Ganser A, Hoelzer D. Myelodysplastic syndromes: clinical features. Semin Hematol. Jul 1996;33(3):177-85. [Medline].
Ingram W, Lim ZY, Mufti GJ. Allogeneic transplantation for myelodysplastic syndrome (MDS). Blood Rev. Jun 5 2006;[Medline].
Jackson GH, Carey PJ, Cant AJ, et al. Myelodysplastic syndromes in children [letter]. Br J Haematol. May 1993;84(1):185-6. [Medline].
Jacobs RH, Cornbleet MA, Vardiman JW, et al. Prognostic implications of morphology and karyotype in primary myelodysplastic syndromes. Blood. Jun 1986;67(6):1765-72. [Medline].
Juneja SK, Imbert M, Jouault H, Scoazec JY, Sigaux F, Sultan C. Haematological features of primary myelodysplastic syndromes (PMDS) at initial presentation: a study of 118 cases. J Clin Pathol. Oct 1983;36(10):1129-35. [Medline]. [Full Text].
Kahn A. Abnormalities of erythrocyte enzymes in dyserythropoiesis and malignancies. Clin Haematol. Feb 1981;10(1):123-38. [Medline].
Koeffler HP, Golde DW. Human preleukemia. Ann Intern Med. Aug 1980;93(2):347-53. [Medline].
Larson RA. Myelodysplasia: when to treat and how. Best Pract Res Clin Haematol. 2006;19(2):293-300. [Medline].
Loh ML, Sakai DS, Flotho C, Kang M, Fliegauf M, Archambeault S. Mutations in CBL occur frequently in juvenile myelomonocytic leukemia. Blood. Aug 27 2009;114(9):1859-63. [Medline].
Luna-Fineman S, Shannon KM, Atwater SK, et al. Myelodysplastic and myeloproliferative disorders of childhood: a study of 167 patients. Blood. Jan 15 1999;93(2):459-66. [Medline]. [Full Text].
Luna-Fineman S, Shannon KM, Lange BJ. Childhood monosomy 7: epidemiology, biology, and mechanistic implications. Blood. Apr 15 1995;85(8):1985-99. [Medline]. [Full Text].
Maldonado JE, Maigne J, Lecoq D. Comparative electron-microscopic study of the erythrocytic line in refractory anemia (preleukemia) and myelomonocytic leukemia. Nouv Rev Fr Hematol Blood Cells. 1976;17(1-2):167-85. [Medline].
Martin S, Baldock SC, Ghoneim AT, Child JA. Defective neutrophil function and microbicidal mechanisms in the myelodysplastic disorders. J Clin Pathol. Oct 1983;36(10):1120-8. [Medline]. [Full Text].
McKenna RW. Myelodysplasia and myeloproliferative disorders in children. Am J Clin Pathol. Dec 2004;122 Suppl:S58-69. [Medline].
Mecucci C, Tricot G, Boogaerts M, Van den Berghe H. An identical translocation between chromosome 1 and 15 in two patients with myelodysplastic syndromes [published erratum appears in Br J Haematol 1987 Apr;65(4):508]. Br J Haematol. Mar 1986;62(3):439-45. [Medline].
Moir DJ, Jones PA, Pearson J, et al. A new translocation, t(1;3) (p36;q21), in myelodysplastic disorders. Blood. Aug 1984;64(2):553-5. [Medline].
Nand S, Godwin JE. Hypoplastic myelodysplastic syndrome. Cancer. Sep 1 1988;62(5):958-64. [Medline].
Negendank W, Weissman D, Bey TM, et al. Evidence for clonal disease by magnetic resonance imaging in patients with hypoplastic marrow disorders. Blood. Dec 1 1991;78(11):2872-9. [Medline]. [Full Text].
Newman DR, Pierre RV, Linman JW. Studies on the diagnostic significance of hemoglobin F levels. Mayo Clin Proc. Mar 1973;48(3):199-202. [Medline].
Niemeyer CM, Baumann I. Myelodysplastic syndrome in children and adolescents. Semin Hematol. Jan 2008;45(1):60-70. [Medline].
O'Donnell MR, Nademanee AP, Snyder DS, et al. Bone marrow transplantation for myelodysplastic and myeloproliferative syndromes. J Clin Oncol. Nov 1987;5(11):1822-6. [Medline].
Ogawa M. Differentiation and proliferation of hematopoietic stem cells. Blood. Jun 1 1993;81(11):2844-53. [Medline].
Passmore SJ, Hann IM, Stiller CA, et al. Pediatric myelodysplasia: a study of 68 children and a new prognostic scoring system. Blood. Apr 1 1995;85(7):1742-50. [Medline]. [Full Text].
Raskind WH, Tirumali N, Jacobson R, et al. Evidence for a multistep pathogenesis of a myelodysplastic syndrome. Blood. Jun 1984;63(6):1318-23. [Medline].
Rosenthal DS, Moloney WC. Refractory dysmyelopoietic anemia and acute leukemia. Blood. Feb 1984;63(2):314-8. [Medline].
Russell NH, Keenan JP, Bellingham AJ. Thrombocytopathy in preleukaemia: association with a defect of thromboxane A2 activity. Br J Haematol. Mar 1979;41(3):417-25. [Medline].
Ruter B, Wijermans PW, Lubbert M. Superiority of prolonged low-dose azanucleoside administration? Results of 5-aza-2'-deoxycytidine retreatment in high-risk myelodysplasia patients. Cancer. Apr 15 2006;106(8):1744-50. [Medline].
Sasaki H, Manabe A, Kojima S, et al. Myelodysplastic syndrome in childhood: a retrospective study of 189 patients in Japan. Leukemia. Nov 2001;15(11):1713-20. [Medline].
Scheres JM, Hustinx TW, Holdrinet RS, et al. Translocation 1;7 in dyshematopoiesis: possibly induced with a nonrandom geographic distribution. Cancer Genet Cytogenet. Aug 1984;12(4):283-94. [Medline].
Schulman I, Pierce M. Studies on thrombopoiesis.I.A factor in normal plasma required for platelet production; chronic thrombocytopenia due to its deficiency. Blood. 1960;16:943.
Scoazec JY, Imbert M, Crofts M, et al. Myelodysplastic syndrome or acute myeloid leukemia? A study of 28 cases presenting with borderline features. Cancer. May 15 1985;55(10):2390-4. [Medline].
Silverman LR, Mufti GJ. Methylation inhibitor therapy in the treatment of myelodysplastic syndrome. Nat Clin Pract Oncol. Dec 2005;2 Suppl 1:S12-23. [Medline].
Sun EC, Yen YM, Ip T, Otsuka NY. Peripheral circulation in patients with myelodysplasia. J Pediatr Orthop. Nov-Dec 2003;23(6):714-7. [Medline].
Takagi S, Tanaka O, Origasa H, Miura Y. Prognostic significance of magnetic resonance imaging of femoral marrow in patients with myelodysplastic syndromes. J Clin Oncol. Jan 1999;17(1):277-83. [Medline].
Tricot G, De Wolf-Peeters C, Hendrickx B, Verwilghen RL. Bone marrow histology in myelodysplastic syndromes. I. Histological findings in myelodysplastic syndromes and comparison with bone marrow smears. Br J Haematol. Jul 1984;57(3):423-30. [Medline].
Tricot G, De Wolf-Peeters C, Vlietinck R, Verwilghen RL. Bone marrow histology in myelodysplastic syndromes. II. Prognostic value of abnormal localization of immature precursors in MDS. Br J Haematol. Oct 1984;58(2):217-25. [Medline].
Tricot G, De Wolf-Peeters C, Vlietinck R, Verwilghen RL. The importance of bone marrow biopsy in myelodysplastic disorders. Bibl Haematol. 1984;(50):31-40. [Medline].
Woodard P, Barfield R, Hale G, et al. Outcome of hematopoietic stem cell transplantation for pediatric patients with therapy-related acute myeloid leukemia or myelodysplastic syndrome. Pediatr Blood Cancer. Sep 9 2005;[Medline].
Woods WG, Barnard DR, Alonzo TA, et al. Prospective study of 90 children requiring treatment for juvenile myelomonocytic leukemia or myelodysplastic syndrome: a report from the Children's Cancer Group. J Clin Oncol. Jan 15 2002;20(2):434-40. [Medline].
Woolfrey AE, Gooley TA, Sievers EL, et al. Bone marrow transplantation for children less than 2 years of age with acute myelogenous leukemia or myelodysplastic syndrome. Blood. Nov 15 1998;92(10):3546-56. [Medline]. [Full Text].
Yoshida Y, Oguma S, Uchino H, Maekawa T. Refractory myelodysplastic anaemias with hypocellular bone marrow. J Clin Pathol. Jul 1988;41(7):763-7. [Medline]. [Full Text].
Yusuf U, Frangoul HA, Gooley TA, et al. Allogeneic bone marrow transplantation in children with myelodysplastic syndrome or juvenile myelomonocytic leukemia: the Seattle experience. Bone Marrow Transplant. Apr 2004;33(8):805-14. [Medline].

