Bone Marrow and Leukemia

Question 1

Myel- or Myelo-

Answer 1

marrow

spinal cord

non-lympoid hemic cells

Question 2

myeloid

Answer 2

myeloid leukemia: non-lymphoid leukemia

Myeloid: Erythroid ratio → non-lymphoid precurors to erythroid precursors

Question 3

Myelocyte

Answer 3

neutrophilic myelocyte, eosinophilic myelocyte

Question 4

Myelitis

Answer 4

inflammation of marrow

Clearer to say ostermyelitis

Question 5

Myelogenous

Answer 5

marrow or non-lymphoid

Question 6

Indications for bone marrow examination

Answer 6

• to pursue the possible causes of unexplained:
  
  • nonregenerative anemia, especially persistent
  • Neutropenia
  • Thrombocytopenia
  • Pancytopenia
  • Lymphocytosis, … lymphoid neoplasia
  • Thrombocytosis, especially extreme
  • Erythrocytosis, Erythroid neoplasia
  • Mastocytemia
  • Atypical or immature cells in blood films
  • Hyperproteinemia, .. myeloma or B-lymphocyte neoplasia
  • Hypercalcemia, .. lympoid neoplasia

Question 7

Bone Marrow as it really is:

Answer 7

Question 8

Bone Marrow:

Aspiration Cytology:

Advantages

Answer 8

rapid turnover time

better assessment of cell morphology

Provides material for other tests flow cytometry

Provides relative quantity of cell types present

Question 9

Bone Marrow:

Aspiration Cytology:

Drawbacks

Answer 9

may not represent all cells

Question 10

Bone Marrow:

Core biopsy

Advantages

Answer 10

evaluation of marrow architecture

Explians reason for ‘dry tap’ - when no cells are obtained on aspiration

Question 11

Bone Marrwo:

Core biopsy

Draw backs

Answer 11

slow processing

More difficult to assess cell morphology

Question 12

Bone Marrow Needles:

For aspiration

Answer 12

Illinois sternal needle

Question 13

Bone Marrow Needles:

Core Biopsys

Answer 13

Jamshidi Marrow Needle

Question 14

Location for Marrow Aspiration:

Large Animals

Answer 14

Sternum

Question 15

Major Steps of Marrow Examination:

Know the questions that are being asked

Answer 15

Eg, Dog has a nonregenerative anemai for at least a week

Why isn’t the marrow producing erythrocytes?

Are all erythroid cells decreased?

Is the erythroid series complete and maturation orderly?

Are there cells taht indiciate abnormal maturation?

Is there evidence of a maturation arrest?

Answers provide clues for diagnosis

Question 16

Major Steps of a marrow examination:

Conccurent CBC data

Answer 16

same day as marrow aspirate.

Question 17

Major steps of a marrow examination:

Cellularity of marrow sample

Answer 17

Highly cellular

Low cellularity

The interpretation of the sample is only as good as the sample quality

Question 18

Cellularity of Marrow Sample:

Hypercellular sample

Answer 18

most likely representative

Question 19

Cellularity of marrow sample:

Hypocellular

Answer 19

may or may not be representative

Question 20

Cellularity of marrow Particles

Answer 20

Hemic cells percentage (Hemic cell to fat cell ratio)

Normal is 25% to 75%

Question 21

Cellularity of marrow particles:

Low %

Answer 21

hypocellular marrow fragment

Question 22

Cellularity of marrow Particles:

High %

Answer 22

hypercellular marrow fragment

Best indicator of marrow cellularity in an aspirate

Question 23

Normocellular

Answer 23

Question 24

Aplastic / Hypoplastic Marrow

Hypocellylar

Answer 24

slow decrease in hematopoitic cells is balanced by increased fat cells

Easily collected by aspiration

Question 25

Rapid Depletion of Hematopoietic cells

Answer 25

Sinus Rupture → hemorrhage → Collapse of reticular meshwork → Rebuild → repopulate Right: canine parvovirus Left: Feline Panleukopenia, early recovery

Question 26

Hypercellular

Answer 26

Question 27

Major Steps of a marrow examination: Assess number of megakaryocytes

Answer 27

Sample cellularity Subjective assessment in a normal animal with platelets WRI, expect ~4-5 per particle Expect more if decreased platelet concentration

Question 28

Major Steps of a Marrow Examination: Identify Iron Pigment

Answer 28

Hemosiderin: Golden to brown pigment May appear black in thick areas Might use special stains

Question 29

Major Steps of a Marrow Examination: Determine Myeloid to Erythroid Ratio

Answer 29

500 cell count Myeloid, erythroid, and lymphoid cells are included in the count of the 500 cells counted, determine the myeloid to erythroid ratio Refference interval for healthy, non-anemic animla Generally ~1:1 to 3:1 Probably more realistic 1:1 to 2.5:1

Question 30

Major Steps of a marrow examination: Assess maturation of cell lines

Answer 30

Question 31

Assess maturation of cell lines: Synchronicity

Answer 31

progressive decrease in cell and nuclear size Nucleus becomes pyknotic and is extruded Cytoplasm changes color from blue to gray to orange

Question 32

Atypical / Significant Findings in Marrow of Blood: Absence

Answer 32

of cell that should be in the bone marrow or maturation arrest

Question 33

Atypical / Significant Findings in Marrow of Blood: Neoplastic Cells

Answer 33

hemic cells → leukemia non-hemic cells → metastatic cells

Question 34

Atypical / Significant Findings in Marrow of Blood: Proplastic cells

Answer 34

reactive lymphocytes shift toward immaturity in neutrophils Regenerative response in erythroid line

Question 35

Leukemia

Answer 35

neoplasia of hemic cells that arise in either bone marrow or splenic red pulp (WBC, RBC, Platelet or their precursors) Many types based on cell type and stage of maturation

Question 36

Acute leukemia

Answer 36

rapid proliferation; typically many medium or large immature cells

Question 37

Chronic leukemia

Answer 37

slower proliferation; relatively well-differentiated hemic cells

Question 38

Lymphoproliferative disease

Answer 38

lymphoid neoplasia must tyr to differentiate between lymphoid leukemia and stage-V lymphoma

Question 39

Myeloproliferative disease

Answer 39

non-lymphoid hemic neoplasia

Question 40

Identifying Leukemic Cells

Answer 40

Goal → determine lineage of neoplastic cell * Methods: * microscopic evaluation of Wright-stained cells * Other diagnostic techniques * microscopic evaluation of cytochemical-stained cells * Immunophenotyping of cells * PCR for antigen receptor rearrangement