Bone Marrow and Leukemia Flashcards
Myel- or Myelo-
marrow
spinal cord
non-lympoid hemic cells
myeloid
myeloid leukemia: non-lymphoid leukemia
Myeloid: Erythroid ratio → non-lymphoid precurors to erythroid precursors
Myelocyte
neutrophilic myelocyte, eosinophilic myelocyte
Myelitis
inflammation of marrow
Clearer to say ostermyelitis
Myelogenous
marrow or non-lymphoid
Indications for bone marrow examination
- 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
Bone Marrow as it really is:
Bone Marrow:
Aspiration Cytology:
Advantages
rapid turnover time
better assessment of cell morphology
Provides material for other tests flow cytometry
Provides relative quantity of cell types present
Bone Marrow:
Aspiration Cytology:
Drawbacks
may not represent all cells
Bone Marrow:
Core biopsy
Advantages
evaluation of marrow architecture
Explians reason for ‘dry tap’ - when no cells are obtained on aspiration
Bone Marrwo:
Core biopsy
Draw backs
slow processing
More difficult to assess cell morphology
Bone Marrow Needles:
For aspiration
Illinois sternal needle
Bone Marrow Needles:
Core Biopsys
Jamshidi Marrow Needle
Location for Marrow Aspiration:
Large Animals
Sternum
Major Steps of Marrow Examination:
Know the questions that are being asked
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
Major Steps of a marrow examination:
Conccurent CBC data
same day as marrow aspirate.
Major steps of a marrow examination:
Cellularity of marrow sample
Highly cellular
Low cellularity
The interpretation of the sample is only as good as the sample quality
Cellularity of Marrow Sample:
Hypercellular sample
most likely representative
Cellularity of marrow sample:
Hypocellular
may or may not be representative
Cellularity of marrow Particles
Hemic cells percentage (Hemic cell to fat cell ratio)
Normal is 25% to 75%
Cellularity of marrow particles:
Low %
hypocellular marrow fragment
Cellularity of marrow Particles:
High %
hypercellular marrow fragment
Best indicator of marrow cellularity in an aspirate
Normocellular
Aplastic / Hypoplastic Marrow
Hypocellylar
slow decrease in hematopoitic cells is balanced by increased fat cells
Easily collected by aspiration
Rapid Depletion of Hematopoietic cells
Sinus Rupture → hemorrhage → Collapse of reticular meshwork → Rebuild → repopulate
Right: canine parvovirus
Left: Feline Panleukopenia, early recovery
Hypercellular
Major Steps of a marrow examination:
Assess number of megakaryocytes
Sample cellularity
Subjective assessment
in a normal animal with platelets WRI, expect ~4-5 per particle
Expect more if decreased platelet concentration
Major Steps of a Marrow Examination:
Identify Iron Pigment
Hemosiderin:
Golden to brown pigment
May appear black in thick areas
Might use special stains
Major Steps of a Marrow Examination:
Determine Myeloid to Erythroid Ratio
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
Major Steps of a marrow examination:
Assess maturation of cell lines
Assess maturation of cell lines:
Synchronicity
progressive decrease in cell and nuclear size
Nucleus becomes pyknotic and is extruded
Cytoplasm changes color from blue to gray to orange
Atypical / Significant Findings in Marrow of Blood:
Absence
of cell that should be in the bone marrow or maturation arrest
Atypical / Significant Findings in Marrow of Blood:
Neoplastic Cells
hemic cells → leukemia
non-hemic cells → metastatic cells
Atypical / Significant Findings in Marrow of Blood:
Proplastic cells
reactive lymphocytes
shift toward immaturity in neutrophils
Regenerative response in erythroid line
Leukemia
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
Acute leukemia
rapid proliferation; typically many medium or large immature cells
Chronic leukemia
slower proliferation; relatively well-differentiated hemic cells
Lymphoproliferative disease
lymphoid neoplasia
must tyr to differentiate between lymphoid leukemia and stage-V lymphoma
Myeloproliferative disease
non-lymphoid hemic neoplasia
Identifying Leukemic Cells
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
