Acute Lymphoblastic Leukemia

Overview

Definition

Acute lymphoblastic leukemia/ lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum (ALL/LBL) are hematologic malignancies characterized by the pathological proliferation of lymphoid precursor cells (primarily the B and T cell lineages)
in the 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, with subsequent displacement Displacement The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate. Defense Mechanisms of other blood cell precursors.

Classification

WHO system 2016 (supersedes the French-American-British classification):

• B cell ALL/LBL ( B-ALL B-ALL A leukemia/lymphoma found predominantly in children and adolescents and characterized by a high number of lymphoblasts and solid tumor lesions. Frequent sites involve lymph nodes, skin, and bones. It most commonly presents as leukemia. Non-Hodgkin Lymphomas/LBL) subclassified based on molecular and cytogenetic features:
  • B-ALL B-ALL A leukemia/lymphoma found predominantly in children and adolescents and characterized by a high number of lymphoblasts and solid tumor lesions. Frequent sites involve lymph nodes, skin, and bones. It most commonly presents as leukemia. Non-Hodgkin Lymphomas/LBL with recurrent genetic abnormalities:
    • t(12;21)(p13.2;q22.1): most common genetic lesion in childhood ALL/LBL
    • t(9;22); BCR-ABL1 fusion 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 (Philadelphia 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)
    • t(v;11q23); KMT2A rearranged
    • t(12;21)(p13.2;q22.1); ETV6-RUNX1
    • Hyperdiploidy (> 50 chromosomes Chromosomes 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. DNA Types and Structure)
    • Hypodiploidy (< 46 chromosomes Chromosomes 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. DNA Types and Structure)
    • t(5;14)(q31.1;q32.3); IL3-IGH
    • t(1;19)(q23;p13.3); TCF3-PBX1
  • B-ALL B-ALL A leukemia/lymphoma found predominantly in children and adolescents and characterized by a high number of lymphoblasts and solid tumor lesions. Frequent sites involve lymph nodes, skin, and bones. It most commonly presents as leukemia. Non-Hodgkin Lymphomas/LBL, not otherwise specified
• T cell ALL/LBL (T-ALL/LBL)

Epidemiology and Etiology

Epidemiology

• Most common childhood cancer:
  • About 85% of cases manifest in childhood.
  • In children, it is 5 times more common than acute myeloid leukemia Acute Myeloid Leukemia Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the uncontrolled proliferation of myeloid precursor cells. Seen predominantly in older adults, AML includes an accumulation of myeloblasts and a replacement of normal marrow by malignant cells, which leads to impaired hematopoiesis. Acute Myeloid Leukemia ( AML AML Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the uncontrolled proliferation of myeloid precursor cells. Seen predominantly in older adults, AML includes an accumulation of myeloblasts and a replacement of normal marrow by malignant cells, which leads to impaired hematopoiesis. Acute Myeloid Leukemia).
• Affects more boys than girls
• Peak 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: 
  • 2–5 years of age
  • Again at > 65 years of age
• 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 of 3.4 cases in children per 100,000 population
• Worse 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 in adults

Etiology

• Risk factors: 
  • Ionizing radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma
  • Chemical exposure (benzene, prior chemotherapy Chemotherapy Osteosarcoma)
  • Human T cell leukemia virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology I (HTLV-I), endemic in Japan and the Caribbean, leads to adult T cell leukemia/ lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum.
• Increased risk in the following conditions with genetic abnormalities:
  • Down syndrome Down syndrome Down syndrome, or trisomy 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac, gastrointestinal, ocular, and auditory systems. Down syndrome (Trisomy 21)
  • Bloom syndrome
  • Ataxia-telangiectasia Ataxia-telangiectasia Ataxia-telangiectasia, also known as Louis-Bar syndrome, is a neurocutaneous syndrome, which involves multiple systems but mainly affects the neurological system. Ataxia-telangiectasia is an autosomal recessive genetic disorder caused by a mutation in the ATM gene (ATM serine/threonine kinase or the ataxia-telangiectasia mutated gene). Ataxia-telangiectasia
  • Neurofibromatosis

Mnemonic

• To recall the differentiation of ALL versus chronic leukemia, “remember your ABCs”:
  • Acute
  • Blasts predominate
  • Common in Children
  • Drastic course
  • Elderly (2nd peak 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)
  • Few mature WBCs cause Fevers
• For chronic, it is the opposite:
  • Mature cells predominate
  • Presents in middle-aged and older adults
  • Less debilitating course
  • Elevated WBCs and fewer instances 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/ infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease

Pathophysiology

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

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 starts with a hematopoietic stem cell, which is prompted to divide and differentiate with appropriate chemical stimuli (hemopoietic growth factors).

• Lymphoid stem cells give rise to lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes: Histology:
  • T cells T cells Lymphocytes responsible for cell-mediated immunity. Two types have been identified – cytotoxic (t-lymphocytes, cytotoxic) and helper T-lymphocytes (t-lymphocytes, helper-inducer). They are formed when lymphocytes circulate through the thymus gland and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen. T cells: Types and Functions
  • B cells B cells Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation. B cells: Types and Functions
  • Natural killer (NK) cells
• Myeloid stem cells eventually differentiate into 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, erythrocytes Erythrocytes 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, 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 ( neutrophils Neutrophils Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes. Innate Immunity: Phagocytes and Antigen Presentation, basophils Basophils Granular leukocytes characterized by a relatively pale-staining, lobate nucleus and cytoplasm containing coarse dark-staining granules of variable size and stainable by basic dyes. Innate Immunity: Phagocytes and Antigen Presentation, eosinophils Eosinophils Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin. Innate Immunity: Phagocytes and Antigen Presentation), and monocytes Monocytes Large, phagocytic mononuclear leukocytes produced in the vertebrate bone marrow and released into the blood; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles. Innate Immunity: Phagocytes and Antigen Presentation:
  • IL-3 stimulates the differentiation of multipotent 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 into myeloid progenitor cells Myeloid progenitor cells Stem cells derived from hematopoietic stem cells. Derived from these myeloid progenitor cells are the megakaryocytes; erythroid cells; myeloid cells; and some dendritic cells. Acute Myeloid Leukemia.
  • Granulocyte macrophage colony-stimulating factor Granulocyte macrophage colony-stimulating factor An acidic glycoprotein of mw 23 kda with internal disulfide bonds. The protein is produced in response to a number of inflammatory mediators by mesenchymal cells present in the hemopoietic environment and at peripheral sites of inflammation. GM-CSF is able to stimulate the production of neutrophilic granulocytes, macrophages, and mixed granulocyte-macrophage colonies from bone marrow cells and can stimulate the formation of eosinophil colonies from fetal liver progenitor cells. GM-CSF can also stimulate some functional activities in mature granulocytes and macrophages. White Myeloid Cells: Histology ( GM-CSF GM-CSF An acidic glycoprotein of mw 23 kda with internal disulfide bonds. The protein is produced in response to a number of inflammatory mediators by mesenchymal cells present in the hemopoietic environment and at peripheral sites of inflammation. GM-CSF is able to stimulate the production of neutrophilic granulocytes, macrophages, and mixed granulocyte-macrophage colonies from bone marrow cells and can stimulate the formation of eosinophil colonies from fetal liver progenitor cells. GM-CSF can also stimulate some functional activities in mature granulocytes and macrophages. White Myeloid Cells: Histology) → differentiation from myeloid progenitors to 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 ( neutrophils Neutrophils Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes. Innate Immunity: Phagocytes and Antigen Presentation) and monocytes Monocytes Large, phagocytic mononuclear leukocytes produced in the vertebrate bone marrow and released into the blood; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles. Innate Immunity: Phagocytes and Antigen Presentation 
  • IL-5 → differentiation to eosinophils Eosinophils Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin. Innate Immunity: Phagocytes and Antigen Presentation
  • 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 (TPO) → differentiation to thrombocytes ( 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)
  • 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 → differentiation to erythrocytes Erythrocytes 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 ( 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)

Pathogenesis

• Genetic changes affect the expression and function of transcription factors Transcription Factors Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process. Stages of Transcription in stem cell maturation.
• The changes include:
  • 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 mutations affecting PAX5, ETV6
  • Polymorphic variants of ARID5B, CDKN2A, and IKZF1
• Hematopoietic progenitor cells do not differentiate into functional cells, leading to defective maturation of the lymphocyte precursors: 
  • B lineage: 85%
  • T lineage: 10%–15%
  • NK lineage: < 1%
• In acute leukemias, abnormal cells proliferate but do not differentiate into mature blood cells:
  • Leukemic cells occupy the 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 space, suppressing normal 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 → leukopenia, thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia, and 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
  • Dysfunctional and immature blasts Blasts Injuries resulting when a person is struck by particles impelled with violent force from an explosion. Blast causes pulmonary contusion and hemorrhage, laceration of other thoracic and abdominal viscera, ruptured ear drums, and minor effects in the central nervous system. Blunt Chest Trauma eventually enter the bloodstream, infiltrating other organs. 

Clinical Presentation

General clinical features

• About 6% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are asymptomatic.
• Hepatomegaly and 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 (most common findings on presentation) can manifest as:
  • Abdominal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • Abdominal distension
  • Anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa
  • Weight loss Weight loss Decrease in existing body weight. Bariatric Surgery
• Lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy (nontender, firm, rubbery)
• 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
• Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
  • Associated with 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 infiltration 
  • Children can present with a limp or difficulty in bearing weight.
• Hematologic abnormalities:
  • 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:
    • Pallor
    • Tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children, fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia
  • Thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia:
    • Ecchymoses
    • Petechiae Petechiae Primary Skin Lesions
  • WBC count may be normal, low, or high, but shows abnormal function and presents as:
    • Frequent or recurrent infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease 
    • 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
• Less frequent: 
  • 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 from meningeal spread (< 5%)
  • Painless unilateral testicular enlargement (< 1%)
  • Mediastinal mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast (associated with T-ALL/LBL): 
    • Can cause superior vena cava syndrome Superior vena cava syndrome A condition that occurs when the obstruction of the thin-walled superior vena cava interrupts blood flow from the head, upper extremities, and thorax to the right atrium. Obstruction can be caused by neoplasms; thrombosis; aneurysm; or external compression. The syndrome is characterized by swelling and/or cyanosis of the face, neck, and upper arms. Lung Cancer
    • Can lead to respiratory difficulty (from compression Compression Blunt Chest Trauma)

Acute lymphoblastic leukemia vs acute myeloid leukemia Acute Myeloid Leukemia Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the uncontrolled proliferation of myeloid precursor cells. Seen predominantly in older adults, AML includes an accumulation of myeloblasts and a replacement of normal marrow by malignant cells, which leads to impaired hematopoiesis. Acute Myeloid Leukemia

Diagnosis

Diagnostic findings

• CBC with differential: 
  • 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, thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia
  • Varying WBCs
• Peripheral smear: lymphoblasts Lymphoblasts Lymphocytosis
  • Scant basophilic cytoplasm (usually lacks granules)
  • Prominent nuclei
  • Inconspicuous/indistinct nucleoli
  • Condensed chromatin Chromatin The material of chromosomes. It is a complex of dna; histones; and nonhistone proteins found within the nucleus of a cell. DNA Types and Structure
• 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 examination: 
  • Hypercellular
  • Heavily packed lymphoblasts Lymphoblasts Lymphocytosis 
• Cytochemistry:
  • PAS staining: often positive (some cells have PAS-positive granules)
  • Myeloperoxidase Myeloperoxidase Acute Myeloid Leukemia ( MPO MPO Acute Myeloid Leukemia): negative 
  • Terminal deoxynucleotidyl transferase: positive
• Immunophenotyping Immunophenotyping Process of classifying cells of the immune system based on structural and functional differences. The process is commonly used to analyze and sort T-lymphocytes into subsets based on CD antigens by the technique of flow cytometry. Non-Hodgkin Lymphomas (using flow cytometry Flow cytometry Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake. X-linked Agammaglobulinemia):
  • Characterizes antigens or markers on tumor Tumor Inflammation cells:
    • B-ALL B-ALL A leukemia/lymphoma found predominantly in children and adolescents and characterized by a high number of lymphoblasts and solid tumor lesions. Frequent sites involve lymph nodes, skin, and bones. It most commonly presents as leukemia. Non-Hodgkin Lymphomas/LBL: Most are positive for CD10, CD19, CD20, CD24, cytoplasmic CD22, and CD-79a.
    • T-ALL/LBL: positive for CD3 CD3 Complex of at least five membrane-bound polypeptides in mature T-lymphocytes that are non-covalently associated with one another and with the T-cell receptor. The CD3 complex includes the gamma, delta, epsilon, zeta, and eta chains (subunits). When antigen binds to the T-cell receptor, the CD3 complex transduces the activating signals to the cytoplasm of the T-cell. The CD3 gamma and delta chains (subunits) are separate from and not related to the gamma/delta chains of the T-cell receptor. T cells: Types and Functions (CD2–8 are seen); negative for B cell antigens
  • Aids AIDS Chronic HIV infection and depletion of CD4 cells eventually results in acquired immunodeficiency syndrome (AIDS), which can be diagnosed by the presence of certain opportunistic diseases called AIDS-defining conditions. These conditions include a wide spectrum of bacterial, viral, fungal, and parasitic infections as well as several malignancies and generalized conditions. HIV Infection and AIDS in classification and determining treatment and 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
• Genetic analysis:
  • Identifies mutations
  • Important in 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

Additional tests

• Serum chemistry: may suggest tumor lysis syndrome Tumor lysis syndrome Tumor lysis syndrome is a potentially lethal group of metabolic disturbances that occurs when large numbers of cancer cells are killed rapidly. The lysed cells release their intracellular contents into the bloodstream, resulting in the development of hyperkalemia, hyperuricemia, hyperphosphatemia, hypocalcemia, and acute kidney injury. Tumor Lysis Syndrome or other metabolic complications
• Coagulation profile
• Lumbar puncture Lumbar Puncture Febrile Infant:
  • To evaluate leukemic CNS involvement
  • All children must be evaluated prior to therapy, as CNS involvement affects management.
• Imaging:
  • CT chest: evaluation of T-ALL/LBL (associated with mediastinal mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast)
  • Echocardiogram Echocardiogram Transposition of the Great Vessels or cardiac scan Cardiac Scan The creation and display of functional images showing where the blood is flowing into the myocardium by following over time the distribution of tracers injected into the bloodstream. Nuclear Imaging: pretreatment evaluation of cardiac function (as it can be adversely affected by chemotherapy Chemotherapy Osteosarcoma)

Acute lymphoblastic leukemia vs acute myeloid leukemia Acute Myeloid Leukemia Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the uncontrolled proliferation of myeloid precursor cells. Seen predominantly in older adults, AML includes an accumulation of myeloblasts and a replacement of normal marrow by malignant cells, which leads to impaired hematopoiesis. Acute Myeloid Leukemia

Management

Treatment

Chemotherapy Chemotherapy Osteosarcoma, which can span 2–3 years, is highly effective in young patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship.

• Induction therapy:
  • Initial chemotherapy Chemotherapy Osteosarcoma is given:
    • To eradicate tumor Tumor Inflammation cells (to < 5% blasts Blasts Injuries resulting when a person is struck by particles impelled with violent force from an explosion. Blast causes pulmonary contusion and hemorrhage, laceration of other thoracic and abdominal viscera, ruptured ear drums, and minor effects in the central nervous system. Blunt Chest Trauma)
    • To achieve normal 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 
  • Regimen:
    • Vincristine Vincristine An antitumor alkaloid isolated from vinca rosea. Microtubule and Topoisomerase Inhibitors, corticosteroids Corticosteroids Chorioretinitis, asparaginase 
    • With/without anthracycline (doxorubicin or daunorubicin Daunorubicin A very toxic anthracycline aminoglycoside antineoplastic isolated from streptomyces peucetius and others, used in treatment of leukemia and other neoplasms. Antitumor Antibiotics)
  • Tyrosine Tyrosine A non-essential amino acid. In animals it is synthesized from phenylalanine. It is also the precursor of epinephrine; thyroid hormones; and melanin. Synthesis of Nonessential Amino Acids kinase inhibitors (TKIs) are used in cases of t(9;22) translocation (Philadelphia 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). 
  • Adverse effects (from drug toxicity Toxicity Dosage Calculation or rapid eradication of tumor Tumor Inflammation cells) include:
    • Tumor lysis syndrome Tumor lysis syndrome Tumor lysis syndrome is a potentially lethal group of metabolic disturbances that occurs when large numbers of cancer cells are killed rapidly. The lysed cells release their intracellular contents into the bloodstream, resulting in the development of hyperkalemia, hyperuricemia, hyperphosphatemia, hypocalcemia, and acute kidney injury. Tumor Lysis Syndrome
    • Bleeding or thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus
    • Infection
    • Allergic reaction/ anaphylaxis Anaphylaxis An acute hypersensitivity reaction due to exposure to a previously encountered antigen. The reaction may include rapidly progressing urticaria, respiratory distress, vascular collapse, systemic shock, and death. Type I Hypersensitivity Reaction
    • Neuropathy Neuropathy Leprosy (from vincristine Vincristine An antitumor alkaloid isolated from vinca rosea. Microtubule and Topoisomerase Inhibitors)
    • Hypothalamus-pituitary-adrenal gland suppression Suppression Defense Mechanisms (from corticosteroids Corticosteroids Chorioretinitis)
• CNS prophylaxis Prophylaxis Cephalosporins:
  • Recommended in all children
  • Begins in the induction phase and administered throughout the treatment period
  • Protocols include:
    • Intrathecal chemotherapy Chemotherapy Osteosarcoma 
    • With/without CNS radiotherapy (associated with cognitive impairment, decreased white matter White Matter The region of central nervous system that appears lighter in color than the other type, gray matter. It mainly consists of myelinated nerve fibers and contains few neuronal cell bodies or dendrites. Brown-Séquard Syndrome volume, secondary brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification tumors)
• Consolidation Consolidation Pulmonary Function Tests: 
  • Further courses of chemotherapy Chemotherapy Osteosarcoma to remove the remaining tumor Tumor Inflammation cells
  • Goals:
    • To prevent regrowth
    • To decrease tumor Tumor Inflammation burden
    • To reduce the risks from drug-resistant leukemic cells
  • Begins after complete remission Remission A spontaneous diminution or abatement of a disease over time, without formal treatment. Cluster Headaches is achieved
  • Regimens include:
    • Cytarabine Cytarabine A pyrimidine nucleoside analog that is used mainly in the treatment of leukemia, especially acute non-lymphoblastic leukemia. Cytarabine is an antimetabolite antineoplastic agent that inhibits the synthesis of DNA. Its actions are specific for the s phase of the cell cycle. It also has antiviral and immunosuppressant properties. Antimetabolite Chemotherapy
    • Methotrexate Methotrexate An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. Antimetabolite Chemotherapy
    • Anthracyclines Anthracyclines Organic compounds that have a tetrahydronaphthacenedione ring structure attached by a glycosidic linkage to the amino sugar daunosamine. Antitumor Antibiotics (e.g., daunorubicin Daunorubicin A very toxic anthracycline aminoglycoside antineoplastic isolated from streptomyces peucetius and others, used in treatment of leukemia and other neoplasms. Antitumor Antibiotics)
    • Alkylating agents (e.g., cyclophosphamide Cyclophosphamide Precursor of an alkylating nitrogen mustard antineoplastic and immunosuppressive agent that must be activated in the liver to form the active aldophosphamide. It has been used in the treatment of lymphoma and leukemia. Its side effect, alopecia, has been used for defleecing sheep. Cyclophosphamide may also cause sterility, birth defects, mutations, and cancer. Immunosuppressants)
    • Epipodophyllotoxins (e.g., etoposide Etoposide A semisynthetic derivative of podophyllotoxin that exhibits antitumor activity. Etoposide inhibits DNA synthesis by forming a complex with topoisomerase II and DNA. This complex induces breaks in double stranded DNA and prevents repair by topoisomerase II binding. Accumulated breaks in DNA prevent entry into the mitotic phase of cell division, and lead to cell death. Etoposide acts primarily in the g2 and s phases of the cell cycle. Microtubule and Topoisomerase Inhibitors)
• Maintenance treatment: 
  • Less intensive treatment for 1–2 years
  • Regimen:
    • Daily oral 6-mercaptopurine 6-Mercaptopurine An antimetabolite antineoplastic agent with immunosuppressant properties. It interferes with nucleic acid synthesis by inhibiting purine metabolism and is used, usually in combination with other drugs, in the treatment of or in remission maintenance programs for leukemia. Antimetabolite Chemotherapy ( 6-MP 6-MP An antimetabolite antineoplastic agent with immunosuppressant properties. It interferes with nucleic acid synthesis by inhibiting purine metabolism and is used, usually in combination with other drugs, in the treatment of or in remission maintenance programs for leukemia. Antimetabolite Chemotherapy)
    • Weekly methotrexate Methotrexate An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. Antimetabolite Chemotherapy 
    • Periodic vincristine Vincristine An antitumor alkaloid isolated from vinca rosea. Microtubule and Topoisomerase Inhibitors, prednisone Prednisone A synthetic anti-inflammatory glucocorticoid derived from cortisone. It is biologically inert and converted to prednisolone in the liver. Immunosuppressants, intrathecal therapy
• Allogeneic stem cell transplantation for high-risk ALL such as:
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with Philadelphia chromosome-positive ALL 
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with a poor initial response to induction therapy

Supportive therapy and monitoring

• During treatment:
  • Monitor 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 response.
  • Monitor chemotherapy Chemotherapy Osteosarcoma side effects, which can include:
    • 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 suppression Suppression Defense Mechanisms 
    • Stomatitis Stomatitis Stomatitis is a general term referring to inflammation of the mucous membranes of the mouth, which may include sores. Stomatitis can be caused by infections, autoimmune disorders, allergic reactions, or exposure to irritants. The typical presentation may be either solitary or a group of painful oral lesions. Stomatitis (mouth sores)
    • Diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
  • Improve symptoms and prevent infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease:
    • RBC and platelet transfusions for 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 and thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia
    • Granulocyte-colony stimulating factor for neutropenia Neutropenia Neutrophils are an important component of the immune system and play a significant role in the eradication of infections. Low numbers of circulating neutrophils, referred to as neutropenia, predispose the body to recurrent infections or sepsis, though patients can also be asymptomatic. Neutropenia
    • Only inactive vaccinations during chemotherapy Chemotherapy Osteosarcoma
    • Trimethoprim-sulfamethoxazole prophylaxis Prophylaxis Cephalosporins for pneumocystis carinii pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia 
    • Herpes simplex Herpes Simplex A group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluid-filled vesicles with a raised erythematous base on the skin or mucous membrane. It occurs as a primary infection or recurs due to a reactivation of a latent infection. Congenital TORCH Infections prophylaxis Prophylaxis Cephalosporins with acyclovir Acyclovir A guanosine analog that acts as an antimetabolite. Viruses are especially susceptible. Used especially against herpes. Herpes Zoster (Shingles)
  • If with 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, especially accompanying neutropenia Neutropenia Neutrophils are an important component of the immune system and play a significant role in the eradication of infections. Low numbers of circulating neutrophils, referred to as neutropenia, predispose the body to recurrent infections or sepsis, though patients can also be asymptomatic. Neutropenia, broad-spectrum Broad-Spectrum Fluoroquinolones antibiotics are given.
  • Dietary modification (adjust for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with mucositis Mucositis Stomatitis is a general term referring to inflammation of the mucous membranes of the mouth, which may include sores. Stomatitis can be caused by infections, autoimmune disorders, allergic reactions, or exposure to irritants. The typical presentation may be either solitary or a group of painful oral lesions. Stomatitis, neutropenic diet)
• Monitor for relapse Relapse Relapsing Fever:
  • Relapse Relapse Relapsing Fever rate: 10%–15% in children
  • Symptoms similar to those seen in the initial presentation
  • Areas of relapse Relapse Relapsing Fever:
    • 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
    • CNS
    • Testis

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

• Children (< 15 years): cure rate > 85%
• 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 declines with increasing age: cure rate of 30%–40% in adults ( ≥ 40 years)
• Better 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 is associated with:
  • Age < 30 years
  • Women
  • WBC count < 30,000/µL
  • No adverse cytogenetics
  • Translocation between chromosomes Chromosomes 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. DNA Types and Structure 12 and 21
  • Hyperdiploidy (leukemic cells with > 46 chromosomes Chromosomes 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. DNA Types and Structure)
  • Complete remission Remission A spontaneous diminution or abatement of a disease over time, without formal treatment. Cluster Headaches within 4 weeks
• Worse 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 is associated with:
  • Age > 60 years
  • Men
  • High WBC count (> 100,000/µL)
  • Adverse cytogenetics with translocations t(9;22) or Philadelphia 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
  • Hypodiploidy (leukemic cells with < 46 chromosomes Chromosomes 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. DNA Types and Structure)

Acute lymphoblastic leukemia versus acute myeloid leukemia Acute Myeloid Leukemia Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the uncontrolled proliferation of myeloid precursor cells. Seen predominantly in older adults, AML includes an accumulation of myeloblasts and a replacement of normal marrow by malignant cells, which leads to impaired hematopoiesis. Acute Myeloid Leukemia

Differential Diagnosis

• AML AML Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the uncontrolled proliferation of myeloid precursor cells. Seen predominantly in older adults, AML includes an accumulation of myeloblasts and a replacement of normal marrow by malignant cells, which leads to impaired hematopoiesis. Acute Myeloid Leukemia: a hematologic neoplasm with malignant 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 and uncontrolled proliferation of myeloid precursors. Acute myeloid leukemia Acute Myeloid Leukemia Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the uncontrolled proliferation of myeloid precursor cells. Seen predominantly in older adults, AML includes an accumulation of myeloblasts and a replacement of normal marrow by malignant cells, which leads to impaired hematopoiesis. Acute Myeloid Leukemia, seen predominantly in the elderly, is characterized by the accumulation of myeloblasts. The clinical presentation consisting of fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia, pallor, bleeding, 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, and infection is related to 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, thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia, and lack of functional WBCs. Mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast effects of malignant infiltration (in bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types, liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy, and spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen: Anatomy) are less common (than ALL). Peripheral blood smear Blood smear Myeloperoxidase Deficiency and 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 show myeloblasts and the presence of Auer rods Auer Rods Acute Myeloid Leukemia. Treatment is mainly using chemotherapy Chemotherapy Osteosarcoma. 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 varies according to the age of onset and type of leukemia.
• CML CML 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 malignant proliferation of the granulocytic cell line with a fairly normal differentiation. The underlying genetic abnormality is the Philadelphia 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, an abbreviated 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 22 resulting from reciprocal (9;22)(q34;q11) translocation. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship have constitutional symptoms Constitutional Symptoms Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis, sternal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, and 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. Elevated WBC count and increased numbers of immature cells in a peripheral smear are revealed after laboratory tests. In 10% of blast crisis Blast crisis An advanced phase of chronic myelogenous leukemia, characterized by a rapid increase in the proportion of immature white blood cells (blasts) in the blood and bone marrow to greater than 30%. Chronic Myeloid Leukemia, there is an increase in lymphoblasts Lymphoblasts Lymphocytosis like ALL/LBL. Philadelphia 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 is demonstrated in the myeloid cells Myeloid Cells The classes of bone marrow-derived blood cells in the monocytic series (monocytes and their precursors) and granulocytic series (granulocytes and their precursors). White Myeloid Cells: Histology in CML CML 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.
• CLL CLL Chronic lymphocytic leukemia (CLL) is a hematologic malignancy characterized by excess production of monoclonal B lymphocytes in the peripheral blood. When the involvement is primarily nodal, the condition is called small lymphocytic lymphoma (SLL). The disease usually presents in older adults, with a median age of 70 years. Chronic Lymphocytic Leukemia: a hematologic malignancy Malignancy Hemothorax characterized by the excess production of monoclonal B lymphocytes B lymphocytes Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation. B cells: Types and Functions in the peripheral blood. When the involvement is primarily nodal, the condition is called small lymphocytic lymphoma Small Lymphocytic Lymphoma Chronic Lymphocytic Leukemia ( SLL SLL Chronic Lymphocytic Leukemia). Chronic lymphocytic leukemia Chronic Lymphocytic Leukemia Chronic lymphocytic leukemia (CLL) is a hematologic malignancy characterized by excess production of monoclonal B lymphocytes in the peripheral blood. When the involvement is primarily nodal, the condition is called small lymphocytic lymphoma (SLL). The disease usually presents in older adults, with a median age of 70 years. Chronic Lymphocytic Leukemia usually presents in the elderly and has a median age of 70 years. Diagnosis is usually made when abnormal lymphocytosis Lymphocytosis WBCs develop from stem cells in the bone marrow and are called leukocytes when circulating in the bloodstream. Lymphocytes are 1 of the 5 subclasses of WBCs. Lymphocytosis is an increase in the number or proportion of the lymphocyte subclass of WBCs, often as a result of an immune response to infection (known as reactive lymphocytosis). Lymphocytosis is seen in laboratory findings. Cytopenias Cytopenias IPEX Syndrome can also be seen. Lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes: Histology appear mature but are functionally incompetent; thus, recurrent infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease are possible. 
• Lymphocytosis Lymphocytosis WBCs develop from stem cells in the bone marrow and are called leukocytes when circulating in the bloodstream. Lymphocytes are 1 of the 5 subclasses of WBCs. Lymphocytosis is an increase in the number or proportion of the lymphocyte subclass of WBCs, often as a result of an immune response to infection (known as reactive lymphocytosis). Lymphocytosis: Infectious diseases (infectious mononucleosis Mononucleosis Infectious mononucleosis (IM), also known as “the kissing disease,” is a highly contagious viral infection caused by the Epstein-Barr virus. Its common name is derived from its main method of transmission: the spread of infected saliva via kissing. Clinical manifestations of IM include fever, tonsillar pharyngitis, and lymphadenopathy. Mononucleosis, HIV infection HIV infection Human immunodeficiency virus (HIV), a single-stranded RNA virus belonging to the Retroviridae family, is the etiologic agent of acquired immunodeficiency syndrome (AIDS). The human immunodeficiency virus is a sexually transmitted or blood-borne infection that attacks CD4+ T lymphocyte cells, macrophages, and dendritic cells, leading to eventual immunodeficiency. HIV Infection and AIDS, TB TB Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis complex bacteria. The bacteria usually attack the lungs but can also damage other parts of the body. Approximately 30% of people around the world are infected with this pathogen, with the majority harboring a latent infection. Tuberculosis spreads through the air when a person with active pulmonary infection coughs or sneezes. Tuberculosis) and other noninfectious conditions ( autoimmune diseases Autoimmune diseases Disorders that are characterized by the production of antibodies that react with host tissues or immune effector cells that are autoreactive to endogenous peptides. Selective IgA Deficiency, hypersensitivity) can result in aberrant lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes: Histology. Elevated lymphocyte levels can persist for weeks to months. An underlying condition is usually revealed by history, examination, and laboratory workup.