Lecture 5 9/5/24

Question 1

What are the indications for bone marrow sampling?

Answer 1

-persistent/unexplained abnormalities in peripheral blood
-suspicion of certain infectious organisms/neoplasms
-staging of certain neoplasms
-estimation of iron stores

Question 2

What are the characteristics of a bone marrow aspirate?

Answer 2

-cytology evaluation
-better for evaluating individual cells
-more common
-individual cell morphology is important for diagnosing most bone marrow abnormalities

Question 3

What are the characteristics of a bone marrow core biopsy?

Answer 3

-histopathology evaluation
-better for evaluating cellularity and megakaryocyte numbers
-typically performed when aspirates are unsuccessful
-important for diagnosing certain bone marrow abnormalities

Question 4

What is the most common site of bone marrow collection in small and large animals?

Answer 4

small: proximal humerus
large: sternum/ribs

Question 5

What type of sample is needed for a bone marrow aspirate?

Answer 5

blood and flecks of marrow in an EDTA/anticoagulant

Question 6

What type of sample is needed for a bone marrow core biopsy?

Answer 6

solid piece of tissue in formalin

Question 7

What is the importance of bone marrow cellularity evaluation?

Answer 7

identify if there is an increase or decrease in number of some cell type within the marrow

Question 8

What is the myeloid:erythroid ratio?

Answer 8

relative numbers of myeloid cells to nucleated erythroid precursors

Question 9

How is the myeloid:erythroid ratio interpreted?

Answer 9

along with marrow cellularity and CBC results

Question 10

What abnormalities can a myeloid:erythroid ratio help identify?

Answer 10

-myeloid hyperplasia
-myeloid hypoplasia
-erythroid hyperplasia
-erythroid hypoplasia

Question 11

What is the normal myeloid:erythroid ratio in most species?

Answer 11

between 1:1 and 2:1

Question 12

What does an increased M:E ratio possibly indicate?

Answer 12

-increased myeloid cells/myeloid hyperplasia
-decreased erythroid cells/erythroid hypoplasia

Question 13

What does a decreased M:E ratio possibly indicate?

Answer 13

-decreased myeloid cells/myeloid hypoplasia
-increased erythroid cells/erythroid hyperplasia

Question 14

What is hyperplasia?

Answer 14

physiologic response to loss, consumption, or destruction of mature cells

Question 15

What are some examples of hyperplasia?

Answer 15

-hemorrhage: leads to erythroid hyperplasia
-inflammation: leads to myeloid hyperplasia
-immune-mediated thrombocytopenia: leads to megakaryocytic hyperplasia

Question 16

What is hypoplasia?

Answer 16

indication of suppressed hematopoiesis of one or more cell lines

Question 17

What are some examples of hypoplasia?

Answer 17

-anemia of inflammation: leads to erythroid hypoplasia
-chronic kidney disease: leads to erythroid hypoplasia

Question 18

What is ineffective hematopoiesis?

Answer 18

marrow tries to produce cells but they die before they mature (PIMA)

Question 19

What is bone marrow hypoplasia/aplasia?

Answer 19

stem cell damage, which can result from chemotherapy or some infections

Question 20

What is myelofibrosis?

Answer 20

increased fibrous tissue in the marrow

Question 21

What are the general characteristics of lymphoma?

Answer 21

-common
-originates from lymphoid tissue outside of bone marrow

Question 22

What are the general characteristics of leukemia?

Answer 22

-less common
-originates from hematopoietic tissue

Question 23

What are the types of leukemia?

Answer 23

-acute lymphoid leukemia
-acute myeloid leukemia
-chronic lymphocytic leukemia
-chronic myeloid leukemia

Question 24

Why do the chronic forms of leukemia have a better prognosis that the acute forms?

Answer 24

chronic forms involve mature cells, while acute forms involve immature cells

Question 25

What are the characteristics of acute leukemia?

Answer 25

-blasts in bone marrow and often in blood
-typical CBC pattern includes anemia, neutropenia, thrombocytopenia, and a large number of blasts

Question 26

What are the characteristics of chronic lymphocytic leukemia?

Answer 26

-neoplastic proliferation of mature lymphocytes
-good prognosis
-must distinguish from non-neoplastic lymphocytosis
-marked lymphocytosis

Question 27

What are the characteristics of myelodysplastic syndromes?

Answer 27

-uncommon hematopoietic neoplasm
-associated with FeLV in cats
-defective maturation without apoptosis

Question 28

What are the characteristics of plasmacytoma?

Answer 28

-often solitary masses
-skin or mucous membrane location
-often benign

Question 29

What are the characteristics of multiple myeloma?

Answer 29

-systemic
-arises in bone marrow or spleen
-often produces a monoclonal gammopathy

Question 30

What are the indications for advanced lymphoma/leukemia diagnostics?

Answer 30

-sure that a population of cells is lymphoid, but not sure if they are neoplastic
-sure that a population of cells is neoplastic, but want more information to guide treatment/prognosis

Question 31

What are the characteristics of flow cytometry?

Answer 31

-detects a panel of molecules on cell membranes
-different hematopoietic lineages have different expression patterns that are detected
-liquid sample
-more widely available and common compared to PARR

Question 32

What are the characteristics of PARR?

Answer 32

-PCR reactions amplify B or T antigen receptor genes from all lymphoid cells in a sample
-polyclonal result indicates non-neoplastic population
-monoclonal result indicates neoplastic population
-cytology slide sample

Question 33

What are the characteristics of PARR false positives and negatives?

Answer 33

-false positives/false detection of clonality are not common, but can occur with poorly cellular samples or some tick-borne diseases
-false negatives occur when no clonality is detected despite the animal having neoplasia, and occur about 10-20% of the time

Question 34

What is pancytopenia?

Answer 34

-anemia
-neutropenia
-thrombocytopenia