Myelodysplastic, Myeloproliferative and Lymphoproliferative Diseases – Unit 2.1

A set of 30 vocabulary flashcards summarizing essential terms, genes, classifications, and treatments related to myelodysplastic, myeloproliferative, and lymphoproliferative diseases.

Myelodysplastic Syndromes (MDS)

Clonal hematopoietic stem-cell neoplasms marked by ineffective hematopoiesis, cytopenias, dysplasia, and risk of progression to AML.

Ineffective hematopoiesis

Defective blood-cell production in the bone marrow that leads to peripheral cytopenias despite a usually hypercellular marrow.

Cytopenia

A reduction in the number of mature blood cells (anemia, neutropenia, or thrombocytopenia) commonly seen in MDS.

Dysplasia (hematologic)

Morphologic abnormality of blood or marrow cells indicating defective maturation; a hallmark feature of MDS.

Acute Myeloid Leukemia (AML)

Aggressive myeloid cancer defined by ≥20% blasts in blood or marrow; MDS can transform into AML.

Hematopoietic Stem Cell (HSC)

Multipotent bone-marrow cell capable of self-renewal and giving rise to all blood lineages; primary cell of origin in MDS.

Clonal Hematopoiesis of Indeterminate Potential (CHIP)

Age-related acquisition of leukemic gene mutations in otherwise healthy individuals; may precede overt MDS.

SF3B1 mutation

Spliceosome gene alteration frequently linked to ring sideroblasts in MDS and associated with a favorable prognosis.

TET2 mutation

DNA demethylation gene defect that disrupts epigenetic regulation; common in MDS and CMML.

ASXL1 mutation

Chromatin-modifier gene alteration correlating with poor prognosis and aggressive MDS or CMML.

DNMT3A mutation

DNA-methyltransferase gene defect that promotes clonal expansion in MDS and related disorders.

TP53 mutation

Tumor-suppressor gene alteration; biallelic/multihit changes confer very high AML risk and therapy resistance.

Revised International Prognostic Scoring System (IPSS-R)

Widely used tool that stratifies MDS patients by cytopenias, blast percentage, cytogenetics, and predicts median survival.

MDS with Low Blasts (MDS-LB)

WHO 2022 category with <5% marrow blasts (<2% blood), dysplasia in ≥1 lineage, and generally lower AML risk.

MDS with Increased Blasts (MDS-IB)

High-risk MDS subdivided into IB1 (5–9% marrow blasts) and IB2 (10–19%); notable for greater likelihood of AML transformation.

MDS with isolated del(5q)

Subtype defined by sole deletion of chromosome 5q, <5% blasts, macrocytic anemia, and strong response to lenalidomide.

MDS with biallelic TP53 inactivation

Distinct WHO entity harboring multihit TP53 lesions and complex karyotype; carries a very poor prognosis.

Ring sideroblast

Erythroid precursor containing perinuclear iron-laden mitochondria; ≥15% defines sideroblastic morphology linked to SF3B1 mutation.

Hypomethylating agents

Disease-modifying drugs (azacitidine, decitabine) that inhibit DNA methylation and improve cytopenias in higher-risk MDS.

Luspatercept

Erythroid-maturation agent approved for transfusion-dependent MDS patients, especially those with SF3B1 mutations.

Lenalidomide

Immunomodulatory therapy producing high response rates in MDS with isolated del(5q).

Allogeneic stem cell transplantation

Only curative option for MDS; replaces diseased marrow with donor hematopoietic stem cells.

Refractory Anemia (RA)

FAB category of MDS characterized by anemia, <5% marrow blasts, and low (<10%) risk of AML progression.

Refractory Anemia with Ring Sideroblasts (RARS)

FAB subtype showing ≥15% ring sideroblasts and <5% blasts; corresponds to MDS with SF3B1 mutation in WHO 2022.

Refractory Anemia with Excess Blasts (RAEB)

FAB entity with 5–20% marrow blasts and intermediate AML risk; aligns with MDS-IB in modern classification.

Chronic Myelomonocytic Leukemia (CMML)

Overlap MDS/MPN disorder featuring persistent monocytosis, dysplasia, and <20% blasts; often carries TET2, SRSF2 mutations.

MDS/MPN with Neutrophilia (formerly aCML)

WHO 2022 overlap entity characterized by leukocytosis with immature granulocytes, dysgranulopoiesis, and SETBP1 or ETNK1 mutations.

MDS/MPN with Ring Sideroblasts and Thrombocytosis (MDS/MPN-RS-T)

Overlap syndrome displaying ≥15% ring sideroblasts, platelets ≥450 × 10⁹/L, and frequent SF3B1 plus JAK2 V617F mutations.

Juvenile Myelomonocytic Leukemia (JMML)

Pediatric MDS/MPN overlap disease with monocytosis, splenomegaly, and RAS/MAPK pathway mutations (e.g., PTPN11, NRAS).

SETBP1 mutation

Genetic alteration linked to worse prognosis in MDS/MPN with Neutrophilia and some aggressive myeloid neoplasms.