MPD

Myeloproliferative neoplasms (MPN) constitute one of five categories of myeloid malignancies, according to the World Health Organization (WHO) classification system for hematopoietic tumors *Chronic myelogenous leukemia, BCR-ABL1 positive (CML) *Polycythemia vera (PV) *Primary myelofibrosis (PMF) *Essential thrombocythemia (ET)

* Acute myeloid leukemia (AML) and related precursor neoplasms * Myeloproliferative neoplasms (MPN) - Classic MPN Chronic myelogenous leukemia, BCR-ABL positive (CML) Polycythemia vera (PV) Primary myelofibrosis (PMF) Essential thrombocythemia (ET) - Nonclassic MPN Chronic neutrophilic leukemia (CNL) Chronic eosinophilic leukemia, not otherwise specified (CEL-NOS) Mastocytosis Myeloproliferative neoplasm, unclassifiable (MPN-U)

*Myelodysplastic syndromes (MDS) Refractory cytopenia with unilineage dysplasia (RCUD) Refractory anemia (ring sideroblasts <15% of erythroid precursors) Refractory neutropenia Refractory thrombocytopenia Refractory anemia with ring sideroblasts (RARS; dysplasia limited to erythroid lineage and ring sideroblasts 15% of bone marrow erythroid precursors) Refractory cytopenia with multi-lineage dysplasia (RCMD; ring sideroblast count does not matter) Refractory anemia with excess blasts (RAEB) RAEB-1 (2–4% circulating or 5–9% marrow blasts) RAEB-2 (5–19% circulating or 10–19% marrow blasts or Auer rods present) MDS associated with isolated del(5q) MDS, unclassifiable

*MDS/MPN Chronic myelomonocytic leukemia (CMML) Atypical chronic myeloid leukemia, BCR-ABL1 negative Juvenile myelomonocytic leukemia (JMML) MDS/MPN, unclassifiable Provisional entity: Refractory anemia with ring sideroblasts associated with marked thrombocytosis (RARS-T) *Myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA,c PDGFRB,c or FGFR1c Myeloid and lymphoid neoplasms with PDGFRA rearrangement Myeloid neoplasms with PDGFRB rearrangement Myeloid and lymphoid neoplasms with FGFR1 abnormalities

Definition: Clonal neoplastic myeloproliferative disorder involving erythroid series (erythrocytosis) Also increased granulocytes & Platelets

*The incidence of polycythemia vera in the United States is approximately 5-17 cases per 1 million population per year *The incidence of polycythemia vera is per 1 mlillion per year; Japan has the lowest incidence. *More in Jews *Female>male 1.4:1 *Age years (uncommon below 40)

*The exact cause still unknown ? *Genetic factors are playing a pathogenetic role JAK2 gene mutation Transformation of single HSC into a cell with selective growth advantage that becomes the predominant myeloid progenitor. It can grow independent of erythropoietin

In many patients, abnormal blood counts are noted on a blood test performed for other reasons. Headache AnorexiaAnorexia, weight loss, weakness Abdominal discomfort and early satiety secondary to splenomegalysplenomegaly Easy bruising, bleeding, and/or symptoms of thrombosis Swollen, painful joint(s) secondary to gouty arthritis secondary to hyperuricemia hyperuricemia Thrombosis (arterial>venous) - PriapismThrombosis (arterial>venous) - Priapism, Budd-Chiari syndrome, stroke, TIA or stupor, DVT & Pulm emb Bleeding – less common – Cutaneous, GIT (PU) Left upper quadrant and left shoulder pain as a consequence of splenic infarction and perisplenitis Pruritis especially after hot bath Vasomotor symptoms – tinnitus, dizziness, digital pain (erythromelalgia), sweating

Plethora secondary to polycythemia (dusky color) Petechiae and/or ecchymosis Palpable spleen and/or liver

CBC counts and differential counts with microscopic examination of the peripheral smear Hb ↑, PCV↑, neutrophilia, eosinophilia, basophilia, thrombocytosis Leukocyte alkaline phosphatase (LAP) score normal or increased (to differentiate chronic myelogenous leukemia from other types) Polymerase chain reaction (PCR) or fluorescent in-situ hybridization (FISH) run on peripheral blood can detect JAK2 gene; bcr-abl gene rearrangement (-ve unlike CML). This helps differentiate chronic myelogenous leukemia from other myeloproliferative diseases. Red blood cell mass study (true vs spurious polycythemia)

Serum uric acid level increased Serum lysozyme increased Serum Histamine increased Serum B12 increased Serum EPO – low

BM aspirate & biopsy with cytogenetic study – hypercellular, megakaryocytes increased and arranged in clumps or sheets

1- Familial & congenital polycythemia 2- Secondary Polycythemia Geographical location, hypernephroma, PCKD, uterine leiomyoma, atrial myxoma, liver hamartoma &liver focal hyperplasia, cerebellar hemangiomas Pulmonary & cardiac disease, obst sleep apnea, smoking, high affinity hemoglobins, Post-renal transplant polycythemia 3- Relative polycythemia (spurious) 4- Other MPD

Phlebotomy – periodic control RBC mass & blood viscosity Myelosuppressive agents 1- Hydroxyurea – effective, short acting, safe, no risk of increased malignancy 2- Busulfan – Severe myelosupp, risk of leuk & malig (no more used) 3- Radioactive Phosphorus 32 – elderly pt

4- Interferon α(IFN) – ameliorate disease & pruritis. Drug of choice in pregnant. Symptomatic treatment – Aspirin – low dose judicious use control digital pain & Th Allopurinol Photochemotherapy PUVA – pruritus Hydration – prevent Th

1- Thrombosis 2- Bleeding (esp UGI) 3- PU 4- Gout 5- Iron deficiency 6- Myelofibrosis (Spent phase) 7- Acute leukemia (AML)

Survival after phlebotomy alone 13.9 y Phosphorus treated pt 11.8 y Thrombosis most common cause of death Next is acute leukemia

MPD