Lecture 5 Part 1 Flashcards
(20 cards)
How would you expect the bone marrow to respond to anemia?
Thrombocytopenia?
Leukopenia?
Erythroid hyperplasia
Megakaryocytic hyperplasia
Myeloid hyperplasia
Describe the maturation of platelets
Progenitor stem cells -> megakaryoblast -> promegakaryocyte -> megakaryocyte -> millions of platelets
- undergo endomitosis (replicating without dividing)
Describe the maturation of a RBC
Proliferative:
Rubriblast -> prorubricytes -> rubricytes ->
Maturation only:
Rubricytes -> metarubricytes -> reticulocytes -> erythrocytes
Describe myeloid/ granulocytic maturation
Proliferation:
Myeloblast -> promyelocytes -> myelocytes
Maturation only:
Myelocytes -> metamyelocytes -> bands -> neutrophils
Why might you look for marrow disease?
Unexplained nonregenerative anemia Unexplained cytopenias Abnormal cells in circulation Unexplained increases in cells Monoclonal gammothapy Staging cancers Unexplained hypercalcemia To evaluate iron stores Look for infectious disease
Unexplained cytopenias- tell me about them
May be selective for one cell line or involve all three
EXCLUDING lymphocytes and monocytes
May be hypocellular with inadequate proliferation or hypercellular with inadequate function
What are you looking for when looking for abnormal cells in circulation?
Persistent thrombocytosis
Persistent leukocytosis
Marked neutrophilic left shift without evidence of inflammation
NRBCs without polychromasia
Blast cells or unidentified cells present
What might hyperproteinemia indicate?
Multiple myeloma
Lymphoid neoplasia
Leishmaniasis
Systemic fungal disease like histoplasmosis
What infectious agents might you look for in the marrow?
Cytauxzoon schizonts
Leishmaniasis
Systemic or local fungal infection
What might hypercalcemia indicate?
Lymphoid neoplasms
Multiple myeloma
Metastatic neoplasms
What types of metastasis might you find when checking bone marrow
Lymphoma
Mast cell tumor
Carcinomas or sarcomas
What is M:E
Myeloid to erythroid ratio
If low, means you have more erythrocytes
If high, means you have more myelocytes
NEED pcv and neutrophil count to interpret
When might the M:E ratio be of little value?
If the marrow is hypoplastic or filled with neoplastic cells
low M:E, normal PCV
Low M:E, normal neutrophil count
Changes reflect issues in neutrophilic series
Changes reflect issues in erythrocytes
When is M:E difficult to interpret?
If PCV and neutrophils are abnormal
Tell me about acute reversible bone marrow injuries
Usually transient
Neutropenia usually occurs
If injury is longer than 1-2 weeks, thrombocytopenia and nonregenerative anemia are possible
Marrow should recover if no other complications are present
During recovery, marrow may become hypercellular
Causes of reversible marrow disease
Infection
Drugs/ chemicals- estrogen in dogs and ferrets, phenylbutazone, albendazole, TMS, methimazole
Chemotherapy
Idiopathic, immune mediated (Central IMHA)
Tell me about irreversible marrow injuries (chronic)
Due to a defect in hematopoiesis
Does not spontaneously improve
Causes of irreversible marrow injury
Myelopthisis (replacement of marrow with other cells or abnormal tissue)
Myelodysplasia (FeLV)
Radiation
Chronic exposure to benzene related chemicals (rare in animals)
Myelofibrosis
Replacement of bone marrow with fibrin
Occurs due to several types of marrow injuries (damage to marrow, necrosis, fibrosis)
Hemolytic anemias (central IMHA)
Associated with abnormal growth of hematopoietic cells and metastasis
Radiation
Idipathic causes
