Hematology 425 Leukocyte Neoplasms Russ Morrison November 29, 2006 9/21/2018

Leukocyte Neoplasms Neoplasm is defined as an abnormal tissue that grows by cellular proliferation more rapidly than normal and continues to grow after the stimuli that initiated the new growth ceases A neoplasm may be benign as with a tumor or malignant in cancer(s) A leukocyte neoplasm is abnormal cellular proliferation in the WBC series 9/21/2018

Leukocyte Neoplasms Leukemias are a group of diseases manifested by malignant, unregulated proliferation of cells normally found in the bone marrow Leukemia may involve any of the blood-forming cells or their precursors Leukemia may be found in metastatic lesions throughout the body, in the brain, liver, spleen and lymph nodes 9/21/2018

Leukocyte Neoplasms Though leukemias progress differently, the unregulated proliferating cells have four things in common They usually replace normal marrow They eventually interfere with normal marrow function They may invade other organs The eventually cause death if they go untreated 9/21/2018

Leukocyte Neoplasms Leukemias are relatively new diseases since they were first described in 1845 In 1900, it was reported that acute and chronic leukemias involve different types of WBCs In chronic leukemias, mature cells are predominant while in acute leukemias, immature cells (blasts) hold center stage 9/21/2018

Leukocyte Neoplasms Since the 1900s, leukemias have been studied with the microscope, cytochemical stains, electron microscopy, immunologic nuclear and surface markers and cytogenetic techniques Standardized subclassification of leukemia subtypes leads to better treatments through pharmaceutical research Today, we are at a threshold of development of targeted therapies, better treatments and cures for both the acute and chronic leukemias 9/21/2018

Clinical Classification of Leukemia Leukemias are divided into acute and chronic diseases based on their presenting signs and symptoms as well as the cell type involved Acute leukemias are characterized by abrupt onset of clinical signs (infection, hemorrhage and pallor) and symptoms (fatigue, weakness, bone and joint pain) Death occurs within months in acute leukemia if treatment is not begun 9/21/2018

Clinical Classification of Leukemia WHO classification of acute leukemias requires a minimum of 20% blast forms (myeloid or lymphoid) in either the PB or BM PB WBC counts may be increased, decreased or normal, though typically they are increased Normocytic anemia and neutropenia are classic states, while thrombocytopenia is usually present 9/21/2018

Clinical Classification of Leukemia Chronic leukemias have an insidious onset of signs (pallor, splenomegaly and/or hepatomegaly, weight loss) and symptoms (weakness, fatigue, depression) They usually occur in adults and death occurs years after diagnosis WBC counts are variable, though usually higher than seen in acute leukemia and cell forms are more mature Platelet counts are normal or increased Acute vs Chronic is compared in Table 32-1 9/21/2018

Classification by Cell Type A PB smear can initiate a diagnosis of acute or chronic leukemia Additional information is gathered to subcategorize the lymphocytes in CLL and some of the CMLs using cytochemistry, flow cytometry, PCR and cytogenetics Genetic testing to determine specific gene abnormalities will become standard within the next few years 9/21/2018

Morphologic identification of Lymphoblasts vs myeloblasts 2-3 times the size of a normal lymphocyte Have scant blue cytoplasm Uniform coarse chromatin Inconspicuous nucleoli Myeloblast 3-5 times the size of a normal lymphocyte Moderate grey cytoplasm Uniform fine chromatin 2 or more prominent nucleoli Auer rods 9/21/2018

ALL 9/21/2018

AML (note Auer Rod) 9/21/2018

Morphologic Subtypes of ALL Three morphologic subtypes of “blasts” have been described according to the FAB classification system Little, if any, prognostic information is gained from this classification Subtypes are termed L1, L2 and L3 based on the following descriptions 9/21/2018

ALL – L1 Lymphoblasts Small Scant blue cytoplasm Round nuclei Indistinct nucleoli The most common type of ALL 9/21/2018

ALL – L1 Lymphoblasts 9/21/2018

ALL – L2 Lymphoblasts 2-3 times the size of a normal lymphocyte Moderate cytoplasm Irregular nuclear membrane Prominent nucleoli May resemble AML 9/21/2018

ALL – L2 Lymphoblasts 9/21/2018

ALL – L3 Lymphoblasts Large Midnight blue cytoplasm Cytoplasmic vacuoles are present 3-5 nucleoli 9/21/2018

ALL – L3 Lymphoblasts 9/21/2018

Other Classifications of Acute Leukemias - Cytochemical Cytochemical staining classification systems were developed by FAB The current panel of stains includes myeloperoxidase, Sudan black B, chloroacetate esterase, and nonspecific esterase Table 32-2 shows the FAB classification of acute leukemias by cytochemical reactions 9/21/2018

Other Classifications of Acute Leukemias - immunologic Monoclonal antibodies and flow cytometry added to morphology and cytochemical stains brings the accuracy of identification of leukemic cell lines to 95% The technique is more commonly used for lymphoid rather than myelogenous cell lines A panel of cell line markers is used because no single surface marker is specific Table 32-3 shows the immunologic classification of these cells 9/21/2018

Other Classifications of Acute Leukemias - Cytogenetic Chromosomal alterations aree associated with leukemic cells Cytogenetic studies can be used to detect clonal abnormalities Clonal abnormalities can be of number (ploidy) or of structure (translocations, deletions and rearrangements) 9/21/2018

Other Classifications of Acute Leukemias - Molecular Molecular Diagnostics/PCR are able to identify genetic mutations in both acute and chronic leukemias As these methods develop, the diagnosis and classification of acute and chronic leukemias will be performed by molecular methods 9/21/2018

Acute Leukemias - ALL Acute lymphoblastic leukemia (ALL) is a disease of childhood Most cases occur between the ages of 2 and 10 years of age All is rare in adults, but a second cluster of incidence occurs among elderly patients Treatment of childhood ALL now yields a 90% rate of complete remission with a 60% cure rate 9/21/2018

Acute Leukemias - ALL Adults with ALL do not fare as well having a 68-91% remission rate and a 25-41% cure rate Approximately half of patients with ALL have increased WBC counts and they may or may not have lymphoblasts in the PB Neutropenia, thrombocytopenia and anemia are usually present This pancytopenia causes fatigue, fever and bleeding and there is often lymph node enlargement 9/21/2018

Acute Leukemias - ALL Hepatomegaly and splenomegaly are often present as well as bone pain due to infiltration of leukemic cells into the periosteum Eventually, the meninges are invaded by malignant cells and lymphoblasts are found in the CSF Lymphoblast infiltration into the testes and ovaries is common, especially in relapse 9/21/2018

ALL - Prognosis Prognosis is dependent on the age of the patient at the time of diatnosis It is also related to the lymphoblast load and immunophenotype Chromosomal translocations (ex Philadelphia Chromosome 5(9;22)) are proving to be a strong predictor of adverse treatment outcomes for both children and adults 9/21/2018

ALL - Prognosis Patients 2-10 years of age have the best prognosis Children less than 1 year of age do poorly Children between 1 and 2 have an intermediate success rate, as do teenagers and young adults Lymphoblast count > 20-30 x109/L, hepatosplenomegaly and lymphadenopathy all decrease the effectiveness of treatment and the patients are considered “high risk” 9/21/2018

ALL - Prognosis Other variables showing decreased outcomes include race (native American), karyotypic abnormalities and sex (male) Morphology – The three major FAB classifications FAB-L1, FAB-L2, and FAB-L3 were discussed in Chapter 32 9/21/2018

ALL - Immunophenotyping Morphology is the first tool in distinguishing ALL from AML, but immunophenotyping is the best indicator of a cell’s origin Immunologic classification of ALL should be performed in all cases due to the prognostic implications 9/21/2018

ALL - Treatment Success with treatment is divided by age of presentation Intrathecal methotrexate is used with children Methotrexate is a folate antagonist and kids on this drug will be megaloblastoid Adults are treated with daunorubicin, vincristine and prednisone (all with side effects) Stem cell or bone marrow transplantation is the last line of treatment for unresponsive or relapsed ALL 9/21/2018

Acute Myeloid Leukemia - AML AML is the most common leukemia in children less than 1 year of age AML is rare in older children and adolescents A second age focus of AML occurs among adults 40 years of age AML is rapidly fatal if not treated 8 types of AML (M0 thru M7) have been described 9/21/2018

AML – Clinical Presentation Clinical presentation is nonspecific reflecting the decreased production of normal BM elements WBC count is usually between 5000 and 30,000/mm3, but may be as high as 200,000 or as low as 1000 Myeloblasts are present in the PB of 90% of patients Anemia, thrombocytopenia and neutropenia lead to symptoms of pallor, fatigue, bruising, bleeding and fever with infections 9/21/2018

AML – Clinical Presentation DIC and other bleeding abnormalities occur, especially with M3-promyelocytic and monocytic-M5 forms of AML Infiltration of malignant cells into the gums and mucous membranes, as well as the skin are is seen in M4-myelomonocytic and M5-monocytic types Bone and joint pain is the first symptom in 25% of patients Splenomegaly is seen in half of AML patients, but lymph node enlargement is rare 9/21/2018

AML – Clinical Presentation AML patients do not usually exhibit symptoms when the CNS is infiltrated with blasts Elevated uric acid, potassium and phosphate levels along with decreased calcium (termed tumor-lysis syndrome), renal failure, tetany and lethal heart arrythmias may develop 9/21/2018

AML – Subtypes Micrographs of the AML subtypes are exhibited in the text and atlas The FAB cooperative group has defined 8 subtypes (M0-M8) of AML based on bone marrow morphology and cytochemical reactions In the FAB classification, 2 types of myeloblasts have been described Type 1 have typical blast morphology and no azurophilic granules Type 2 may contain a small number of primary granules 9/21/2018

AML – Subtype M0 Acute myeloblastic leukemia, minimally differentiated Blasts do not display morphologic myeloid characteristics Fewer than 3% of blasts exhibit myeloperoxidase or Sudan black B positivity Auer rods are not sen May express antigen TdT 9/21/2018

AML – Subtype M1 Acute myeloblastic leukemia, without maturation Displays minimal myeloid differentiation Myeloblasts constitute more than 30% of the BM nucleated cells M:E ratio is greater than 1 90% of the erythroid cells are myeloblasts 3% of the myeloblasts show positivity when stained with myeloperoxidse of Sudan black B Easily confused with ALL (L2 type) Accounts for 20% of cases of AML 9/21/2018

AML – Subtype M2 Acute myeloblastic leukemia, with maturation 30% of nucleated cells must be blasts in the BM film and myeloid cells outnumber NRBCs Blasts constitute fewer than 90% of nonerythroid cells and there is maturation beyond the promelycyte in more than 10% of nonerythroid cells Majority of blasts stin positively when stained with myeloperoxidase or Sudan black B Subtype accounts for 30% of cases of AML 9/21/2018

AML Induction therapy in M1 and M2 leukemia is usually effective, resulting in sufficient return of normal marrow responses for an autologous bone marrow transplant Drugs frequently used are daunorubicin and cytosine arabinoside Cardiac monitoring is necessary due to side effects Cytosine arabinoside is active against the nucleus, resulting in a megaloblastoid presentation of the CBC 9/21/2018

AML – Subtype M3 Acute promyelocytic leukemia May be one of two types, hypergranular or microgranular Stain strongly positive with myeloperoxidase M3 patients must be recognized because bleeding problems (DIC) occur when these patients are treated and the granules are released Make up approximately 15% of all AML cases Treatment with all-trans retinoic acid (ATRA) a form of Vitamin A causes the cells to undergo maturation (cells have a defective vitamin A receptor) 9/21/2018

AML – Subtype M4 Acute myelomonocytic leukemia Has malignant cells with both granulocytic and monocytic features BM more than 30% of nucleated cells are blasts When the M:E ratio is greater than 1, more than 20% of nonerythroid cells are monocytic A small percent has moderate eosinophilia (AML-M4Eo), have CSF involvement and a better remission rate and response to chemotherapy 9/21/2018

AML – Subtype M5 Acute monocytic leukemia Accounts for 12% of AML Diagnosis based solely on the BM morphology More than 30% of cells are blasts More than 80% of cells are monocytic, less than 20% granulocytic Two subtypes recognized, M5a and M5b Skin involvemen and gum infiltration may be seen in both types 9/21/2018

AML – M5 – Gum infiltration 9/21/2018

AML – Subtype M6 Acute erythroleukemia Rare, 3% of AML cases The only AML with hyperplasia of erythroid precursors 9/21/2018

AML – Subtype M7 Acute megakaryocytic leukemia The rarest type of AML at <1% of cases In adults, many cases are preceded by a myeloproliferative disorder with pancytopenia or myelofibrosis In children it is more frequent among patients under three years of age with Down syndrome Response to therapy is poor 9/21/2018

Other Acute Myeloid-like Leukemias Acute undifferentiated leukemia and hybrid leukemias are often treated as AML, but are not necessarily related Undifferentiated acute leukemia is a rare disorder in which the lineage of the blasts can not be determined Hybrid leukemias are leukemias with both lymphoid and myeloid characteristics 9/21/2018

Chronic leukemias – lymphocytic disorders There are two major types of chronic lymphoid leukemias Chronic lymphocytic leukemia (CLL) Hairy cell leukemia There are also a few other forms of chronic lymphoid leukemias that are rare and not discussed in this series 9/21/2018

Chronic Lymphocytic Leukemia CLL is the most common type of leukemia Usually occurs in older patients Most commonly found in patients older than 40 (though youngest case was 22) Affects twice as many men as women No specific chromosomal abnormality has been associated with CLL 9/21/2018

CLL – Clinical Course Variable clinical course with most patients living at least 1-2 years after diagnosis Median survival is 6 years and some patients live many years with the disease and die of other causes It is impossible to tell at the time of diagnosis what the estimated life span will be CLL is often discovered when other medical problems such as persistent viral infection are being investigated 9/21/2018

CLL – Clinical Course When symptoms are present, they are usually nonspecific, such as weakness, fatigue, weight loss Lymphadenopathy and marked hepato-splenomegaly are frequent, especially late in the disease The malignant cell in CLL is usually a small, mature-appearing lymphocyte with B-cell immunophenotype Smudge cells are seen in the PB 9/21/2018

CLL – Clinical Course Diagnosis of CLL depends on sustained lymphocyte count greater than 10 x 109/L Other causes of lymphocytosis must be ruled out Subsets of lymphocytes cannot be differentiated by morphology Phenotyping using flow cytometry is a good method to identify clonal expansion 2 staging systems are used for CLL and are presented in table 34-2 (RAI and Binet) 9/21/2018

CLL – Clinical Course Anemia and thrombocytopenia usually appear late in the course of the disease CLL is often associated with autoimmune phenomena AIHA occurs in 15-35% of patients CLL may remain stable or undergo morphologic transformation Patients who have experienced morphologic transformation are less responsive to treatment 9/21/2018

CLL – Clinical Course Initial treatment of CLL involves a “watch-and-wait” approach Eventual treatment of the disease can range from conservative (leukophorresis) to traditional chemotherapy (cytosine arabinoside) to aggressive (bone marrow transplantation) to designer drugs (anti-CD20) 9/21/2018

CLL - PB 9/21/2018

Hairy Cell Leukemia A rare malignant disorder accounting for 2% of all leukemias Usually occurs in middle-aged patients with a median age of 50 years Has an insidious onset characterized by weakness and lethargy Splenomegaly is present in 80% of patients Pancytopenia is characteristic and BM aspirates result in a “dry tap” 9/21/2018

Hairy Cell Leukemia Hairy cells have reniform to oval nuclei with finely granular chromatin and delicate gray cytoplasm with projections that give the cell a “hairy” appearance Immunologically, the hairy cell is a mid- to late B cell Patients may live for many years with the disease; median length of survival is 7 years 9/21/2018

Hairy Cell Leukemia 9/21/2018

Other Chronic Leukemias of Lymphoid Origin Other B-Lymohoid chronic leukemias include Prolymphocytic leukemia Waldenstrom macroglobulinemia Lymphosarcoma cell leukemia Chronic leukemias of T-cell origin are rare and comprise <5% of patients with CLL 9/21/2018

Chronic Myelogenous Leukemia CML is considered a chronic myeloproliferative disorder and is characterized by panmyelosis with a predominance of myeloid component in the BM, PB and other organs Occurs at any age, but most commonly after 45 years of age Weight loss and fatige are the initial symptoms Massive splenomegaly may cause left upper abdominal pain or gastric discomfort 9/21/2018

CML Anemia is present, markedly elevelated WBC counts (50-500 x 109/L or higher) Thrombocytosis, eosinophilia, basophilia and a range of granulocyte maturation with a predominance of myelocytes is seen in the PB Myeloblasts constitute fewer than 10% of circulating leukocytes Occasional NRBCs are seen and the PB resembles a BM aspirate 9/21/2018

CML Pseudo-Pelger-Huet cells, twinning and other nuclear abnormalities may be present The Philadelphia chromosome (a translocation of the long arm of C22 to C9 is present in almost all cases of CML Patients with CML usually undergo a chronic phase that lasts 3 years called the meridian This stage can be prolonged using interferon-α An accelerated phase follows with worsening clinical features that are less responsive to therapy 9/21/2018

CML Approximately 1/3 of patients enter “blast crisis” in which the disease resembles acute leukemia 1/3 of patients entering blast crisis have ALL and 2/3 have AML blast crisis Treatment consists of trying to keep or return the patient to the initial or chronic phase BM or stem cell transplants have shown some promise Development of a targeted anti-tyrosine kinase drug has shown promise in trials 9/21/2018

CML – FISH, Philadelphia Chromosome 9/21/2018

CML 9/21/2018

CML 9/21/2018

CML 9/21/2018