Hematopathology Week 6

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Hematopathology Week 6

• Case 1
• An 11 year-old girl is brought to the emergency
  room

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Initial Presentation

• For several weeks the patient had been
  complaining of tiredness and bone pain in
  multiple locations.
• Her mother noted that she looked pale and was
  developing bruises on her lower extremities.
• For the last several days the patient was running
  a low-grade fever.
• Past medical history was non-contributory.
• Seen in the emergency room, the patient appeared
  a well-nourished child appearing her stated age
  and in mild distress.

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What is Tiredness?

• Common causes of "tiredness" may include
• Lack of sleep
• Disturbed sleep (Insomnia)
• Sleeping difficulty
• General stress
• Jet lag
• Shift work
• Relationship conflict
• New baby
• Pregnancy - Some level of tiredness is common in
  pregnancy but may also indicate medical
  conditions.
• Increased work load
• Generally being "run-down"
• Some illnesses that may cause tiredness include
• Chronic fatigue syndrome
• Hypothyroidism
• Anemia
• Psychological disorders that may cause tiredness
  include
• Depression
• Bulimia nervosa

• You may have to ask the child several open-ended
  questions and give examples.
• For instance, does she mean dyspneic or becomes
  short of breath easily?
• Do her muscles feel weak when walking or arising
  from a sitting or supine position?
• Does she feel light-headed?
• She may also have a combination of these.
• She may feel weak and have no energy, plus she
  may get easily short of breath with exertion.
• You may also ask the parents to tell you what
  they see when she becomes more tired. Is she
  breathing fast or laboriously? Does she have an
  overall lack of energy as manifest by the lack of
  her participation in her usual activities?

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What do we mean by bruising?

• Possibilites
• Child abuse (trauma)
• Certain cultural practices, e.g. cupping or coin
  rubbing
• Platelet abnormalities or decrease in number
• decreased production
• bone marrow malignancy such as leukemia
• bone marrow replacement from other
  non-hematopoietic malignancies
• rare metabolic disease affecting bone marrow
• increased destruction
• immune mediated (ITP)
• TTP, hemolytic uremic syndrome
• DIC from sepsis
• intrinsic abnormalities of the platelet
• abnormalities of blood vessels
• certain vasculitides such as Henoch-Schönlein
  Purpura
• Fragile capillaries from nutritional deficiencies

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When do you consider child abuse?

• Physical findings that are not adequately
  explained by the history are worrisome. The
  history should match the physical findings.
• Less worrisome if the parents simply state they
  dont know how the bruising came about then if
  they gave an explanation that seems unlikely for
  the observed mark or injury.
• Look for patterns in the bruising (finger marks,
  crescent-shaped bruises, and bruising in soft
  tissue areas as well as in protected areas such
  as in the inside of the upper arm).

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PATIENT CBC
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Bone Marrow Biopsy 20X
NORMAL
PATIENT
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Bone Marrow Biopsy 400X
Normal This is a picture of normal bone marrow
at medium magnification. Ordinarily, about one
half of the marrow is filled with red blood
cells, white blood cells, platelets,and the cells
which produce them. The large white cells are fat
cells called steatocytes .
Patient
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Aspirate Smear 1,000 X
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Aspirate Smear 1,000 X

• What is an Auer rod generally diagnostic of
• Acute Myeloid Leukemia
• Some types of acute leukemia are composed of only
  blasts (no differentiating neutrophils, no
  monocytic precursors, just a sea of blasts). In
  those cases, look for Auer rods.
• A blast with an Auer rod can only be a
  myeloblast! It cannot be a lymphoblast, or a
  monoblast, or any other kind of blast. So if you
  see blasts with Auer rods, you know it is some
  type of acute myeloid leukemia.
• Converse not true just because you dont  see
  Auer rods, that does not mean that the blast is
  not a myeloblast. Some myeloblasts have Auer
  rods, and some dont. So if you see Auer rods, it
  is an AML. If you dont, it still could be an AML.

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Flow Cytometry
Table of the cells reactivity for various
antigens
Gating on Blast Cluster
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Fluorescent In-situ Hybridization (FISH)

• Fluorescent in-situ hybridization exposes
  interphase cells to DNA probes that are specific
  for the genetic abnormality under consideration.
• TEL-AML1, is the commonest genetic translocation
  in pediatric ALL, occurring in 25 of B-lineage
  cases. likely that the translocation prevents the
  activation of genes that would normally be turned
  on by AML1. It conveys a good prognosis

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Principle of FISH using EVl1 probe

• Probe composed of two differentially labelled
  contigs specific for the 3q26 locus
• Mody centromeric contig, labelled in green
  fluorochrome, hybridizes to a region extending
  460 kb from the centromeric (3') end of the EVI1
  gene.
• Second, most telomeric contig, labelled with a
  red fluorochrome, is specific for a region
  beginning approximately 500 kb 3' of EVI1 and
  extends 370 kb in a telomeric direction.
• The distance between the hybridization regions
  of the two contigs is 530 kb.
• The breakpoint region associated with 3q26
  abnormalities is indicated.
• Principle of the EVI1 break-apart FISH assay with
  the expected normal and abnormal hybridization
  patterns.

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Example of a Dual Probe AML1 - ETO

• AML1 gene, located at chromosome 21q22, encodes a
  component (CBFa2) of a heterodimeric
  transcription factor complex termed core binding
  factor (CBF), which binds to DNA and activates
  gene expression.
• Chromosomal rearrangements may lead to disruption
  of this gene and development of acute leukemia.
  Twelve AML1 translocations have been identified
  to date, and include sites on chromosomes 1, 2,
  3, 5, 8, 12, 14, 15, 16, 17, 18, and 19.
• AML1 Transcription Factor is fused with ETO (or
  MTG8) in the t(821)(q22q22) translocation.
• The rearrangement is observed in 40 of AML M2
  patients and less frequently in subgroups M1 and
  M4. Overall 7 of AML cases demonstrate the
  abnormality, the majority of which are de novo.

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Dx Acute Lymphocytic Leukemia (ALL)

• PROGNOSIS
• Hyperdiploidy is a good prognostic factor if
  there are gt 50 chromosomes or the DNA index is
  gt1.16.
• Thought that this is due to increased sensitivity
  to anti-metabolites, increased spontaneous
  apoptosis, and a lower tumor burden.
• Children 2 to 10 years of age with early pre-B
  phenotype and hyperploidy, as well as those with
  a t(1221) translocation, have an excellent
  prognosis.
• Three factors have been consistently associated
  with a worse prognosis
• Age under 2, possibly because of the strong
  association of infantile ALL with translocations
  involving the MLL gene on chromosome 11
• Presentation in adolescence or adulthood
• The presence of a t(922)
• Boys continue to do worse than girls even after
  correction for the higher rate of T-cell ALL in
  boys. Induction failure is a very bad prognostic
  sign.

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CASE 2

• A 48 year old with The Case of Excessive
  Nosebleeds

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Patient Lab Results

• What are this patient's most striking laboratory
  results?

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Laboratory Values
What are this patient's most striking laboratory
results?
RBC morphology normocytic/normochromic with
schistocytes present
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Patient Laboratory Results
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Most Likely Diagnosis

• Thromobotic thrombocytopenic purpura (TTP).
• Combination of hemolytic anemia and
  thrombocytopenia suggests a diagnosis of
  disseminated intravascular coagulation (DIC) or
  TTP.
• In DIC, PT and PTT results are increased, while
  in TTP, they are normal. In this case, the
  results of PT and PTT are normal