1. Hematology 425 Leukocyte Neoplasms
Russ Morrison
November 29, 2006
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2. 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
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3. 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
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4. 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
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5. 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
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6. 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
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7. 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
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8. 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
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9. 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
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10. 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
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11. 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
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12. ALL
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13. AML (note Auer Rod)
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14. 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
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15. ALL – L1 Lymphoblasts Small Scant blue cytoplasm Round nuclei
Indistinct nucleoli
The most common type of ALL
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16. ALL – L1 Lymphoblasts
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17. ALL – L2 Lymphoblasts 2-3 times the size of a normal lymphocyte
Moderate cytoplasm
Irregular nuclear membrane
Prominent nucleoli
May resemble AML
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18. ALL – L2 Lymphoblasts
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19. ALL – L3 Lymphoblasts Large Midnight blue cytoplasm
Cytoplasmic vacuoles are present
3-5 nucleoli
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20. ALL – L3 Lymphoblasts
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21. 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
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22. 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
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23. 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)
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24. 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
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25. 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
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26. 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
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27. 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
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28. 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
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29. 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 > x109/L, hepatosplenomegaly and lymphadenopathy all decrease the effectiveness of treatment and the patients are considered “high risk”
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30. 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
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31. 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
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32. 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
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33. 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
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34. 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
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35. 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
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36. 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
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37. 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
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38. 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
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39. 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
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40. 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
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41. 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
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42. 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)
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43. 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
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44. 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
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45. AML – M5 – Gum infiltration
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46. AML – Subtype M6 Acute erythroleukemia Rare, 3% of AML cases
The only AML with hyperplasia of erythroid precursors
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47. 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
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48. 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
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49. 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
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50. 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
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51. 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
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52. 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
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53. 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)
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54. 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
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55. 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)
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56. CLL - PB
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57. 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”
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58. 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
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59. Hairy Cell Leukemia
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60. 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
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61. 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
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62. CML
Anemia is present, markedly elevelated WBC counts ( 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
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63. 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
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64. 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
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65. CML – FISH, Philadelphia Chromosome
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66. CML
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67. CML
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68. CML
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