Myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN) overlap syndromes are a group of rare myeloid malignancies that paradoxically exhibit both dysplastic and proliferative hematopoietic cell characteristics. They share phenotypic features of both MDS, such as dysplasia and cytopenias, and of MPNs, including…
Primary myelofibrosis (PMF) is a Philadelphia chromosome-negative, clonal, myeloproliferative neoplasm (MPN) that is often but not always accompanied by the driver mutations JAK2V617F , calreticulin exon 9 ( CALR ), and the thrombopoietin receptor, MPL515L/K . PMF is clinically characterized…
Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm (MPN) characterized by platelet counts in excess of 450 × 10 9 /L, profound bone marrow (BM) megakaryocyte hyperplasia, leukocytosis, splenomegaly, a clinical course punctuated by hemorrhagic and/ or thrombotic episodes, and…
Under normal conditions, the red blood cell (RBC) mass in humans is tightly controlled and remains relatively constant in a given individual. The numbers of senescent RBCs lost daily are replaced by newly formed ones by a carefully controlled network…
Introduction and Historical Perspective Chronic myeloid leukemia (CML), a rare condition, has had a profound impact on the development of hematology/oncology and modern medicine as a whole ( Fig. 69.1A and B ). The story started in the 1830s with…
Acute lymphoblastic leukemia (ALL) is a heterogeneous group of diseases characterized by clonal proliferation of lymphoid progenitors (lymphoblasts). Improved diagnostic tools permit accurate and prompt diagnosis and aid in evaluation of minimal residual disease (MRD). There have been significant advances…
Serial risk-directed clinical trials have optimized the combination of chemotherapeutic agents and, along with advances in supportive care, have led to current cure rates of childhood acute lymphoblastic leukemia (ALL) exceeding 85% compared with those of less than 10% in…
Introduction Normal lymphoid precursors undergo somatic recombination at their immunoglobulin (Ig) or T-cell receptor (TCR) gene loci, and the successful completion of V(D)J recombination, with the resultant formation of a functional Ig or TCR, is required for the survival of…
Myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal stem cell disorders that result in ineffective hematopoiesis and an increased risk of developing acute myeloid leukemia (AML). Whereas in MDS ineffective hematopoiesis results in progressive cytopenias,…
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a hematopoietic-derived malignancy thought to occur by transformation of plasmacytoid dendritic cells (pDCs) or pDC progenitors. Normal pDCs are immune cells that recognize microbes via Toll-like receptors and are the principal producers of…