Polycythemia Vera

Overview

Definition

Polycythemia Polycythemia An increase in the total red cell mass of the blood. Renal Cell Carcinoma vera (PV) is a chronic myeloproliferative neoplasm characterized by the overproduction of RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology (erythrocytosis), WBCs, and platelets Platelets Platelets are small cell fragments involved in hemostasis. Thrombopoiesis takes place primarily in the bone marrow through a series of cell differentiation and is influenced by several cytokines. Platelets are formed after fragmentation of the megakaryocyte cytoplasm. Platelets: Histology. This triad differentiates PV from erythrocytosis seen with chronic hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage and other conditions.

Classification

• Primary PV is a myeloproliferative disorder.
• Secondary polycythemia Polycythemia An increase in the total red cell mass of the blood. Renal Cell Carcinoma is due to an increase in erythropoietin Erythropoietin Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology ( EPO EPO Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology) caused by environmental circumstances or other conditions:
  • Lung disease/chronic hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage
  • Sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep apnea
  • Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases
  • High altitude
  • EPO-secreting tumors, such as renal cell carcinoma Renal cell carcinoma Renal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma

Epidemiology

• Affects an estimated 44–57 of 100,000 individuals in the US
• Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency is slightly higher in men than women for unclear reasons
• Seen in all ages, but the incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency increases with age and peaks between 50 and 70 years
• Affects all ethnic groups

Etiology and Pathophysiology

Etiology

• Not fully understood
• Most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship have a mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations of the Janus kinase-2 gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics (JAK2) on chromosome Chromosome In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. Basic Terms of Genetics 9, which encodes for a protein essential for RBC production.

Pathophysiology

• The JAK2 gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics is involved in signal transduction Transduction The transfer of bacterial DNA by phages from an infected bacterium to another bacterium. This also refers to the transfer of genes into eukaryotic cells by viruses. This naturally occurring process is routinely employed as a gene transfer technique. Bacteriology for EPO EPO Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology, thrombopoietin Thrombopoietin A humoral factor that stimulates the production of thrombocytes (blood platelets). Thrombopoietin stimulates the proliferation of bone marrow megakaryocytes and their release of blood platelets. The process is called thrombopoiesis. Platelets: Histology, and granulocyte colony-stimulating factor Granulocyte colony-stimulating factor A glycoprotein of mw 25 kda containing internal disulfide bonds. It induces the survival, proliferation, and differentiation of neutrophilic granulocyte precursor cells and functionally activates mature blood neutrophils. Among the family of colony-stimulating factors, G-CSF is the most potent inducer of terminal differentiation to granulocytes and macrophages of leukemic myeloid cell lines. White Myeloid Cells: Histology (G-CSF).
• A JAK2 mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations, found in 98% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with PV, results in enhanced cytokine signaling that results in the increased production of all hematopoietic stem cells Hematopoietic stem cells Progenitor cells from which all blood cells derived. They are found primarily in the bone marrow and also in small numbers in the peripheral blood. Bone Marrow: Composition and Hematopoiesis.
• Other mutations lead to sustained activation of JAK2 kinase, which causes excess blood cell production independent of EPO EPO Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology:
  • Calreticulin (CALR) mutations have been found in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with PV without a JAK2 mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations.
  • Lymphocytic adaptor protein (LNK) mutations have been found in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with isolated erythrocytosis.

Clinical Presentation

Polycythemia Polycythemia An increase in the total red cell mass of the blood. Renal Cell Carcinoma vera is often diagnosed incidentally when a CBC obtained for other reasons reveals increased hemoglobin and hematocrit Hematocrit The volume of packed red blood cells in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, anemia shows a low value; polycythemia, a high value. Neonatal Polycythemia. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship also present with disease-related symptoms or complications.

• Neurologic:
  • Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess
  • Dizziness Dizziness An imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness. Lateral Medullary Syndrome (Wallenberg Syndrome)
  • Visual disturbances
  • Erythromelalgia, a burning pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in the feet or hands accompanied by erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion, pallor, or cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination, in the presence of palpable pulses (29% of cases)
• Dermatologic and musculoskeletal:
  • Plethora Plethora Neonatal Polycythemia (ruddy complexion)
  • Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema), especially after a hot bath or shower (36%)
  • Gouty tophi Tophi Msu deposit in the soft tissue and synovium. Gout
  • Petechiae Petechiae Primary Skin Lesions
• GI:
  • Splenomegaly Splenomegaly Splenomegaly is pathologic enlargement of the spleen that is attributable to numerous causes, including infections, hemoglobinopathies, infiltrative processes, and outflow obstruction of the portal vein. Splenomegaly (36%)
  • Hepatomegaly
  • Epigastric pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • Peptic ulcer Peptic ulcer Peptic ulcer disease (PUD) refers to the full-thickness ulcerations of duodenal or gastric mucosa. The ulcerations form when exposure to acid and digestive enzymes overcomes mucosal defense mechanisms. The most common etiologies include Helicobacter pylori (H. pylori) infection and prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs). Peptic Ulcer Disease disease
• Cardiovascular:
  • Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension (46%)
  • Venous thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus (7%)
  • Arterial thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus
  • Angina pectoris Angina pectoris The symptom of paroxysmal pain consequent to myocardial ischemia usually of distinctive character, location and radiation. It is thought to be provoked by a transient stressful situation during which the oxygen requirements of the myocardium exceed that supplied by the coronary circulation. Stable and Unstable Angina
  • Stroke
  • Intermittent claudication Intermittent claudication A symptom complex characterized by pain and weakness in skeletal muscle group associated with exercise, such as leg pain and weakness brought on by walking. Such muscle limpness disappears after a brief rest and is often relates to arterial stenosis; muscle ischemia; and accumulation of lactate. Thromboangiitis Obliterans (Buerger’s Disease)
• Hematologic (due to platelet dysfunction):
  • Epistaxis Epistaxis Bleeding from the nose. Granulomatosis with Polyangiitis
  • Ecchymosis Ecchymosis Extravasation of blood into the skin, resulting in a nonelevated, rounded or irregular, blue or purplish patch, larger than a petechia. Orbital Fractures
  • Gingival bleeding
  • Major hemorrhage (4%)

Diagnosis

Polycythemia Polycythemia An increase in the total red cell mass of the blood. Renal Cell Carcinoma vera is suspected in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with characteristic physical findings and/or increased levels of hemoglobin and hematocrit Hematocrit The volume of packed red blood cells in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, anemia shows a low value; polycythemia, a high value. Neonatal Polycythemia on a CBC.

Rule out secondary causes of polycythemia Polycythemia An increase in the total red cell mass of the blood. Renal Cell Carcinoma (high EPO EPO Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology levels):

•  High altitude
•  Chronic hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage
•  Paraneoplastic syndrome ( renal cell carcinoma Renal cell carcinoma Renal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma)

Laboratory findings for primary PV:

• CBC and chemistry:
  • Increased:
    • Hemoglobin and hematocrit Hematocrit The volume of packed red blood cells in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, anemia shows a low value; polycythemia, a high value. Neonatal Polycythemia
    • Leukocytes Leukocytes White blood cells. These include granular leukocytes (basophils; eosinophils; and neutrophils) as well as non-granular leukocytes (lymphocytes and monocytes). White Myeloid Cells: Histology
    • Platelets Platelets Platelets are small cell fragments involved in hemostasis. Thrombopoiesis takes place primarily in the bone marrow through a series of cell differentiation and is influenced by several cytokines. Platelets are formed after fragmentation of the megakaryocyte cytoplasm. Platelets: Histology
    • Uric acid Uric acid An oxidation product, via xanthine oxidase, of oxypurines such as xanthine and hypoxanthine. It is the final oxidation product of purine catabolism in humans and primates, whereas in most other mammals urate oxidase further oxidizes it to allantoin. Nephrolithiasis and B12 (not needed for diagnosis)
    • LDH LDH Osteosarcoma
  • Decreased:
    • MCV
    • Iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements
    • EPO EPO Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology
• Peripheral smear: Findings depend on the stage at the time of diagnosis.
  • Erythrocytosis (excess RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology)
  • Dacryocytes (teardrop-shaped RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology)
  • Poikilocytosis (abnormally shaped RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology)
  • Circulating nucleated RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology
  • Hypochromia and microcytosis in the case of iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements deficiency
  • Thrombocytosis
  • Leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus in the absence of fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever or infection
• Testing for JAK2, CALR, and LNK mutations (done sequentially)
• Bone marrow Bone marrow The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells. Bone Marrow: Composition and Hematopoiesis biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma:
  • No bone marrow Bone marrow The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells. Bone Marrow: Composition and Hematopoiesis findings absolutely differentiate PV from other disorders of erythrocytosis.
  • Increased cellularity (versus fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans)
  • Typically shows panmyelosis
  • Large and clumped megakaryocytes
  • Occasional increase in reticulin fibers

Management and Prognosis

Management

• The therapeutic goal is to reduce the hematocrit Hematocrit The volume of packed red blood cells in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, anemia shows a low value; polycythemia, a high value. Neonatal Polycythemia to < 45%.
• Phlebotomy Phlebotomy The techniques used to draw blood from a vein for diagnostic purposes or for treatment of certain blood disorders such as erythrocytosis, hemochromatosis, polycythemia vera, and porphyria cutanea tarda. Hereditary Hemochromatosis is the mainstay of therapy.
• Myelosuppressive therapies:
  • Hydroxyurea Hydroxyurea An antineoplastic agent that inhibits DNA synthesis through the inhibition of ribonucleoside diphosphate reductase. Antimetabolite Chemotherapy 
  • Ruxolitinib Ruxolitinib Targeted and Other Nontraditional Antineoplastic Therapy (JAK2 inhibitor)
  • Interferon
• Low-dose aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) is used to reduce the symptoms of microvascular events.
• Allopurinol Allopurinol A xanthine oxidase inhibitor that decreases uric acid production. It also acts as an antimetabolite on some simpler organisms. Gout Drugs is used for hyperuricemia Hyperuricemia Excessive uric acid or urate in blood as defined by its solubility in plasma at 37 degrees c; greater than 0. 42 mmol per liter (7. 0 mg/dl) in men or 0. 36 mmol per liter (6. 0 mg/dl) in women. Gout.
• Antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines are used to relieve the sensation of pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema).
• In rare cases, stem cell transplantation can be performed.

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas and complications

• Thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus is the most common cause of morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status and death, followed by the complications of myelofibrosis and leukemic transformation Transformation Change brought about to an organism’s genetic composition by unidirectional transfer (transfection; transduction, genetic; conjugation, genetic, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell’s genome. Bacteriology.
• About 10%–30% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship progress to a syndrome compatible with primary myelofibrosis Primary myelofibrosis Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by chronic myeloproliferation with nonclonal fibroblastic deposition, resulting in bone marrow fibrosis. The abnormality stems from genetic mutations of the hematopoietic stem cells (typically, JAK2 mutation). Primary symptoms are anemia and extramedullary hematopoiesis,. Primary Myelofibrosis but with better survival.
• Leukemic transformation Transformation Change brought about to an organism’s genetic composition by unidirectional transfer (transfection; transduction, genetic; conjugation, genetic, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell’s genome. Bacteriology from PV occurs in about 2% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship at 10 years to about 8% at 20 years.

Differential Diagnosis

• Secondary polycythemia Polycythemia An increase in the total red cell mass of the blood. Renal Cell Carcinoma: an increase in RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology due to chronic hypoxemia Hypoxemia Neonatal Respiratory Distress Syndrome, familial erythrocythemia, paraneoplastic syndromes Paraneoplastic syndromes Paraneoplastic syndromes are a heterogeneous group of disorders caused by an abnormal immune response to a neoplasm. The substances produced are not due to the direct effect of the tumor, such as metastasis, mass effect, or invasion. Antibodies, hormones, cytokines, and other substances are generated and affect multiple organ systems. Paraneoplastic Syndromes, or relative polycythemia Polycythemia An increase in the total red cell mass of the blood. Renal Cell Carcinoma due to contraction of plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products volume as seen with dehydration Dehydration The condition that results from excessive loss of water from a living organism. Volume Depletion and Dehydration.
• Essential thrombocytosis (primary thrombocythemia): a nonreactive, chronic myeloproliferative disorder in which excessive proliferation of megakaryocytes and platelets Platelets Platelets are small cell fragments involved in hemostasis. Thrombopoiesis takes place primarily in the bone marrow through a series of cell differentiation and is influenced by several cytokines. Platelets are formed after fragmentation of the megakaryocyte cytoplasm. Platelets: Histology is seen. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are largely asymptomatic but may develop thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus and bleeding.
• Chronic myeloid leukemia Chronic myeloid leukemia Chronic myeloid leukemia is a malignant proliferation of the granulocytic cell line characterized by a fairly normal differentiation. The underlying genetic abnormality is the Philadelphia chromosome, an abbreviated chromosome 22, resulting from reciprocal (9;22)(q34;q11) translocation. Chronic Myeloid Leukemia: a myeloproliferative disorder characterized by an increase in WBCs, including an increased number of granulocytes Granulocytes Leukocytes with abundant granules in the cytoplasm. They are divided into three groups according to the staining properties of the granules: neutrophilic, eosinophilic, and basophilic. Mature granulocytes are the neutrophils; eosinophils; and basophils. White Myeloid Cells: Histology and their immature precursors. Blast cells are also seen occasionally. 
• Primary myelofibrosis Primary myelofibrosis Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by chronic myeloproliferation with nonclonal fibroblastic deposition, resulting in bone marrow fibrosis. The abnormality stems from genetic mutations of the hematopoietic stem cells (typically, JAK2 mutation). Primary symptoms are anemia and extramedullary hematopoiesis,. Primary Myelofibrosis: a clonal disorder arising from the neoplastic transformation Transformation Change brought about to an organism’s genetic composition by unidirectional transfer (transfection; transduction, genetic; conjugation, genetic, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell’s genome. Bacteriology of early hematopoietic stem cells Hematopoietic stem cells Progenitor cells from which all blood cells derived. They are found primarily in the bone marrow and also in small numbers in the peripheral blood. Bone Marrow: Composition and Hematopoiesis. Primary myelofibrosis Primary myelofibrosis Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by chronic myeloproliferation with nonclonal fibroblastic deposition, resulting in bone marrow fibrosis. The abnormality stems from genetic mutations of the hematopoietic stem cells (typically, JAK2 mutation). Primary symptoms are anemia and extramedullary hematopoiesis,. Primary Myelofibrosis is characterized by anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types, bone marrow Bone marrow The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells. Bone Marrow: Composition and Hematopoiesis fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans, extramedullary hematopoiesis Hematopoiesis The development and formation of various types of blood cells. Hematopoiesis can take place in the bone marrow (medullary) or outside the bone marrow (extramedullary hematopoiesis). Bone Marrow: Composition and Hematopoiesis, leukoerythroblastosis, teardrop-shaped RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology, and hepatosplenomegaly Hepatosplenomegaly Cytomegalovirus.
• EPO EPO Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors mutations: a rare familial disorder that can mimic the basic findings of PV (elevated hemoglobin and hematocrit Hematocrit The volume of packed red blood cells in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, anemia shows a low value; polycythemia, a high value. Neonatal Polycythemia with low serum EPO EPO Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology). A positive family history Family History Adult Health Maintenance, early age at disease onset, and the lack of PV-associated clinical findings can help distinguish EPO EPO Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation. Erythrocytes: Histology receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors mutations from primary PV.