Haema 2012; 3(2): 125-133
by Alexandros Makis1, Georgia Avgerinou2, Sophia Polychronopoulou2
1Child Health Department, University of Ioannina Medical School, Ioannina, Greece,
2Department of Paediatric Haematology-Oncology, “Aghia Sophia” Children’s Hospital, Athens, Greece
Abstract
Myelodysplastic syndromes (MDS) comprise a group of clonal hematopoietic stem cell disorders, characterized by ineffective hematopoiesis, quantitative and qualitative abnormalities of the erythroid, myeloid and megakaryocytic cell lineages, and an increased propensity to evolve into acute leukemia. Myelodysplastic syndromes in childhood are rare hematological malignancies with an annual incidence of 1.8 per million. They appear with distinct clinical and laboratory features. To accommodate the characteristics of pediatric MDS, a new, widely accepted classification of myelodysplastic diseases in childhood has greatly facilitated diagnosis. A simple classification scheme based on morphological features and conforming to the WHO (World Health Organisation) suggestions was proposed. It recognizes three diagnostic groups: refractory cytopenia [RC, bone marrow (BM) blasts <5%], refractory anemia with excess of blasts (RAEB, BM blasts 5–20%) and refractory anemia with excess of blasts in transformation (RAEBT, BM blasts 20–30%). In children with MDS, the main symptom is thrombocytopenia and neutropenia, in contrast to adults, in whom the main symptom is anemia. De novo myelodysplastic syndromes arise in previously healthy children, however congenital physical abnormalities often accompanying the disease, strengthen the assumption that predisposing genetic lesions may contribute to the disturbance of hematopoiesis. The pathways leading to the promotion of abnormal and/or malignant hematopoiesis in connection with the prevalent underlying genetic background have not yet been elucidated. Therapeutic interventions include: watch and wait strategy, stem cell transplantation or immunosuppressive therapy. This article reviews classification, diagnosis procedures, pathophysiology, and treatment strategies in MDS in childhood.