Podcast
Questions and Answers
Which of the following is an advantage of bone marrow aspirate over core biopsy?
Which of the following is an advantage of bone marrow aspirate over core biopsy?
- More accurate overall marrow architecture
- Easier individual cell identification
- Better assessment of cellularity
- Superior cell detail (correct)
Which of the following small animal collection sites carries the risk of penetrating the thoracic cavity?
Which of the following small animal collection sites carries the risk of penetrating the thoracic cavity?
- Proximal femur
- Sternum (correct)
- Proximal humerus
- Iliac crest
Why might bone marrow samples from older patients not be representative?
Why might bone marrow samples from older patients not be representative?
- Higher proportion of myeloid cells
- Increased cellularity
- Less active hematopoiesis (correct)
- Increased presence of spicules
After a bone marrow aspirate, what is one of the first steps?
After a bone marrow aspirate, what is one of the first steps?
What does a hypercellular marrow typically indicate?
What does a hypercellular marrow typically indicate?
What is the term for when mature cells are more eosinophilic with more cytoplasm?
What is the term for when mature cells are more eosinophilic with more cytoplasm?
What is the primary staining method for bone marrow evaluation?
What is the primary staining method for bone marrow evaluation?
What is suggested by cells appearing blue to purple after staining?
What is suggested by cells appearing blue to purple after staining?
In what animal is iron storage most prominent in bone marrow?
In what animal is iron storage most prominent in bone marrow?
If evaluating a bone marrow sample at low power, what is the main attribute being assessed?
If evaluating a bone marrow sample at low power, what is the main attribute being assessed?
What does a 'left shift' in myeloid maturation indicate in a bone marrow evaluation?
What does a 'left shift' in myeloid maturation indicate in a bone marrow evaluation?
Which of the following is the best definition of 'myelophthisis'?
Which of the following is the best definition of 'myelophthisis'?
In dogs, what percentage of lymphocytes is considered normal in bone marrow?
In dogs, what percentage of lymphocytes is considered normal in bone marrow?
What does increased numbers of medium to large lymphocytes indicate?
What does increased numbers of medium to large lymphocytes indicate?
What is a likely reason for a nonregenerative anemia?
What is a likely reason for a nonregenerative anemia?
What is the MOST appropriate next step if you are evaluating a patient with cytopenia/pancytopenia and the initial assessment is inconclusive?
What is the MOST appropriate next step if you are evaluating a patient with cytopenia/pancytopenia and the initial assessment is inconclusive?
A veterinarian is preparing to perform a bone marrow aspirate on a dog. Which of the described actions would be MOST detrimental to sample quality?
A veterinarian is preparing to perform a bone marrow aspirate on a dog. Which of the described actions would be MOST detrimental to sample quality?
A bone marrow aspirate is performed on a canine patient with suspected hematopoietic neoplasia. Microscopic evaluation reveals a predominance of fat and only rare hematopoietic cells. How should the results of this test be interpreted?
A bone marrow aspirate is performed on a canine patient with suspected hematopoietic neoplasia. Microscopic evaluation reveals a predominance of fat and only rare hematopoietic cells. How should the results of this test be interpreted?
Which of the following best describes the appropriate fixative for processing a bone marrow core biopsy?
Which of the following best describes the appropriate fixative for processing a bone marrow core biopsy?
A veterinarian is evaluating a bone marrow aspirate smear. After staining, the cells appear smudged with poor morphology and indistinct cellular features. What is the MOST likely underlying cause?
A veterinarian is evaluating a bone marrow aspirate smear. After staining, the cells appear smudged with poor morphology and indistinct cellular features. What is the MOST likely underlying cause?
Which location of the bone marrow is LEAST ideal for bone marrow aspirate?
Which location of the bone marrow is LEAST ideal for bone marrow aspirate?
Which definition is MOST accurate?
Which definition is MOST accurate?
What does a finding of >10 plasma cells per 10x field suggest?
What does a finding of >10 plasma cells per 10x field suggest?
A veterinarian is interpreting a bone marrow aspirate from a cat. The M:E ratio is 5:1. Which of the following statements CORRECTLY interprets this result?
A veterinarian is interpreting a bone marrow aspirate from a cat. The M:E ratio is 5:1. Which of the following statements CORRECTLY interprets this result?
Which of the following CBC findings is the least likely indication for bone marrow evaluation?
Which of the following CBC findings is the least likely indication for bone marrow evaluation?
What is the MOST accurate way to assess bone evaluate cellularity?
What is the MOST accurate way to assess bone evaluate cellularity?
A CBC reveals elevated WBC and a normal red cell line. How would you characterize this?
A CBC reveals elevated WBC and a normal red cell line. How would you characterize this?
True or False: Bone marrow findings can be interpreted without a current CBC
True or False: Bone marrow findings can be interpreted without a current CBC
A dog has PCV of 39, WBC of 25,800, Segs of 20,000, and Bands of 3,000. What can be said about its bone marrow?
A dog has PCV of 39, WBC of 25,800, Segs of 20,000, and Bands of 3,000. What can be said about its bone marrow?
A bone marrow evaluation of a cat reveals average cellularity (~50%) with an M:E ratio of 8.0:1. The myeloid and erythroid lines appear normal. Which of the following most accurately describes the bone marrow?
A bone marrow evaluation of a cat reveals average cellularity (~50%) with an M:E ratio of 8.0:1. The myeloid and erythroid lines appear normal. Which of the following most accurately describes the bone marrow?
What is the expected problem for a dog with bone marrow that shows hypercellular spicules with increased Megakaryocytes and M:E Ratio 1:1
What is the expected problem for a dog with bone marrow that shows hypercellular spicules with increased Megakaryocytes and M:E Ratio 1:1
What level of blasts is considered to be characteristic for a case of myelodysplasia?
What level of blasts is considered to be characteristic for a case of myelodysplasia?
In normal animals, what percentage of hematopoietic cells can be assessed in a bone marrow sample?
In normal animals, what percentage of hematopoietic cells can be assessed in a bone marrow sample?
What is the name of hematopoietic cells with nuclear lobation as the cells mature?
What is the name of hematopoietic cells with nuclear lobation as the cells mature?
What is the site of needle introduction when obtaining bone marrow from the proximal femur in small animals?
What is the site of needle introduction when obtaining bone marrow from the proximal femur in small animals?
In a large animal bone marrow collection from the iliac crest, why should one consider muscles to be strong when performing the collection?
In a large animal bone marrow collection from the iliac crest, why should one consider muscles to be strong when performing the collection?
A veterinarian is evaluating a bone marrow aspirate slide from a 5-year-old FS Cocker Spaniel with hematuria. There are hypercellular spicules, megakaryocytes are increased with an M:E ratio of 1:1. Which of the following descriptions BEST suits the bone marrow?
A veterinarian is evaluating a bone marrow aspirate slide from a 5-year-old FS Cocker Spaniel with hematuria. There are hypercellular spicules, megakaryocytes are increased with an M:E ratio of 1:1. Which of the following descriptions BEST suits the bone marrow?
Which stain is used on bone marrow core biopsies?
Which stain is used on bone marrow core biopsies?
Which of the following is considered an advantage of bone marrow aspirate over core biopsy in veterinary diagnostics?
Which of the following is considered an advantage of bone marrow aspirate over core biopsy in veterinary diagnostics?
When performing a bone marrow aspirate in a small animal, which site is associated with the highest risk of accidental penetration into the thoracic cavity?
When performing a bone marrow aspirate in a small animal, which site is associated with the highest risk of accidental penetration into the thoracic cavity?
Why might bone marrow samples collected from the rib of older animals be less diagnostically reliable compared to younger animals?
Why might bone marrow samples collected from the rib of older animals be less diagnostically reliable compared to younger animals?
After obtaining a bone marrow aspirate sample, what is the CRITICAL immediate next step to ensure optimal sample quality for cytologic evaluation?
After obtaining a bone marrow aspirate sample, what is the CRITICAL immediate next step to ensure optimal sample quality for cytologic evaluation?
A bone marrow aspirate is described as 'hypercellular'. What is the MOST likely general interpretation of this finding?
A bone marrow aspirate is described as 'hypercellular'. What is the MOST likely general interpretation of this finding?
In the context of megakaryocyte maturation in bone marrow, what cellular change is associated with mature cells compared to early precursors?
In the context of megakaryocyte maturation in bone marrow, what cellular change is associated with mature cells compared to early precursors?
What type of stain is PRIMARILY used for the initial cytologic evaluation of bone marrow aspirate smears in veterinary practice?
What type of stain is PRIMARILY used for the initial cytologic evaluation of bone marrow aspirate smears in veterinary practice?
After staining a bone marrow aspirate smear with a Romanovsky stain, hematopoietic cells appear predominantly blue to purple. What is the MOST likely interpretation of this staining characteristic?
After staining a bone marrow aspirate smear with a Romanovsky stain, hematopoietic cells appear predominantly blue to purple. What is the MOST likely interpretation of this staining characteristic?
In which common domestic animal species is iron storage within bone marrow macrophages considered to be MOST prominent under normal physiological conditions?
In which common domestic animal species is iron storage within bone marrow macrophages considered to be MOST prominent under normal physiological conditions?
When initially evaluating a bone marrow aspirate slide at low magnification (e.g., 10x objective), what is the PRIMARY attribute being assessed?
When initially evaluating a bone marrow aspirate slide at low magnification (e.g., 10x objective), what is the PRIMARY attribute being assessed?
In bone marrow evaluation, what does a 'left shift' in myeloid maturation MOST likely indicate?
In bone marrow evaluation, what does a 'left shift' in myeloid maturation MOST likely indicate?
Which of the following BEST defines the term 'myelophthisis' in the context of bone marrow disorders?
Which of the following BEST defines the term 'myelophthisis' in the context of bone marrow disorders?
In a bone marrow aspirate from a healthy dog, what is the approximate NORMAL percentage of lymphocytes expected among all nucleated cells?
In a bone marrow aspirate from a healthy dog, what is the approximate NORMAL percentage of lymphocytes expected among all nucleated cells?
An increased number of medium to large lymphocytes in a bone marrow aspirate, especially if they are morphologically atypical, is MOST suggestive of which condition?
An increased number of medium to large lymphocytes in a bone marrow aspirate, especially if they are morphologically atypical, is MOST suggestive of which condition?
In a patient presenting with nonregenerative anemia, what is the MOST likely underlying bone marrow abnormality?
In a patient presenting with nonregenerative anemia, what is the MOST likely underlying bone marrow abnormality?
If an initial bone marrow assessment is inconclusive in a patient with cytopenia/pancytopenia, what is the MOST appropriate next diagnostic step?
If an initial bone marrow assessment is inconclusive in a patient with cytopenia/pancytopenia, what is the MOST appropriate next diagnostic step?
During a bone marrow aspirate procedure, which action is MOST detrimental to the quality of the sample obtained?
During a bone marrow aspirate procedure, which action is MOST detrimental to the quality of the sample obtained?
A bone marrow aspirate from a dog reveals predominantly fat and rare hematopoietic cells. How should these results be INTERPRETED in the context of suspected hematopoietic neoplasia?
A bone marrow aspirate from a dog reveals predominantly fat and rare hematopoietic cells. How should these results be INTERPRETED in the context of suspected hematopoietic neoplasia?
What is the MOST appropriate fixative for processing a bone marrow core biopsy sample for histopathological evaluation?
What is the MOST appropriate fixative for processing a bone marrow core biopsy sample for histopathological evaluation?
Smudged cells with poor morphology on a bone marrow aspirate smear are MOST likely caused by which factor?
Smudged cells with poor morphology on a bone marrow aspirate smear are MOST likely caused by which factor?
Which of the following bone marrow collection sites is LEAST ideal for obtaining a bone marrow aspirate in small animals due to sample representativeness issues?
Which of the following bone marrow collection sites is LEAST ideal for obtaining a bone marrow aspirate in small animals due to sample representativeness issues?
Which definition is MOST accurate for describing 'aplastic anemia'?
Which definition is MOST accurate for describing 'aplastic anemia'?
A finding of >10 plasma cells per 10x microscopic field in a bone marrow aspirate is STRONGLY suggestive of:
A finding of >10 plasma cells per 10x microscopic field in a bone marrow aspirate is STRONGLY suggestive of:
A feline bone marrow aspirate has a myeloid to erythroid (M:E) ratio of 5:1. How should this result be INTERPRETED?
A feline bone marrow aspirate has a myeloid to erythroid (M:E) ratio of 5:1. How should this result be INTERPRETED?
Which of the following complete blood count (CBC) findings is the LEAST likely indication for a bone marrow evaluation?
Which of the following complete blood count (CBC) findings is the LEAST likely indication for a bone marrow evaluation?
What is the MOST accurate method for quantitatively assessing bone marrow cellularity?
What is the MOST accurate method for quantitatively assessing bone marrow cellularity?
A CBC reveals elevated white blood cell count (WBC) and a normal red blood cell line. How would you CHARACTERIZE this finding in relation to bone marrow?
A CBC reveals elevated white blood cell count (WBC) and a normal red blood cell line. How would you CHARACTERIZE this finding in relation to bone marrow?
True or False: Bone marrow findings can be reliably interpreted in isolation, without considering a concurrently obtained complete blood count (CBC).
True or False: Bone marrow findings can be reliably interpreted in isolation, without considering a concurrently obtained complete blood count (CBC).
A dog has a packed cell volume (PCV) of 39%, WBC of 25,800/µL, segmented neutrophils of 20,000/µL, and band neutrophils of 3,000/µL. What can be INFERRED about its bone marrow status based on these CBC findings?
A dog has a packed cell volume (PCV) of 39%, WBC of 25,800/µL, segmented neutrophils of 20,000/µL, and band neutrophils of 3,000/µL. What can be INFERRED about its bone marrow status based on these CBC findings?
A bone marrow evaluation in a cat reveals average cellularity (~50%) with a myeloid to erythroid (M:E) ratio of 8.0:1. The myeloid and erythroid lines appear morphologically normal. Which BEST describes this marrow?
A bone marrow evaluation in a cat reveals average cellularity (~50%) with a myeloid to erythroid (M:E) ratio of 8.0:1. The myeloid and erythroid lines appear morphologically normal. Which BEST describes this marrow?
A dog's bone marrow shows hypercellular spicules with increased megakaryocytes and an M:E ratio of 1:1. What hematologic problem is MOST expected in this dog based on these findings?
A dog's bone marrow shows hypercellular spicules with increased megakaryocytes and an M:E ratio of 1:1. What hematologic problem is MOST expected in this dog based on these findings?
In cases of myelodysplasia, what percentage of blasts in the bone marrow is generally considered characteristic but below the threshold for acute leukemia?
In cases of myelodysplasia, what percentage of blasts in the bone marrow is generally considered characteristic but below the threshold for acute leukemia?
In normal adult animals, what approximate percentage of hematopoietic cells is expected to be found within a bone marrow sample, with the remainder being fat?
In normal adult animals, what approximate percentage of hematopoietic cells is expected to be found within a bone marrow sample, with the remainder being fat?
What is the general term for hematopoietic cells in which nuclear lobation increases as the cells mature, particularly referring to granulocytic maturation?
What is the general term for hematopoietic cells in which nuclear lobation increases as the cells mature, particularly referring to granulocytic maturation?
When obtaining bone marrow from the proximal femur in small animals, what anatomical landmark indicates the site of needle introduction?
When obtaining bone marrow from the proximal femur in small animals, what anatomical landmark indicates the site of needle introduction?
In large animal bone marrow collection from the iliac crest, why is it important for the muscles to be described as 'strong' in the procedure guidelines?
In large animal bone marrow collection from the iliac crest, why is it important for the muscles to be described as 'strong' in the procedure guidelines?
A bone marrow aspirate from a 5-year-old FS Cocker Spaniel with hematuria shows hypercellular spicules, increased megakaryocytes, and an M:E ratio of 1:1. Which BEST describes this marrow?
A bone marrow aspirate from a 5-year-old FS Cocker Spaniel with hematuria shows hypercellular spicules, increased megakaryocytes, and an M:E ratio of 1:1. Which BEST describes this marrow?
Which stain is typically used on bone marrow core biopsies for routine histopathological evaluation?
Which stain is typically used on bone marrow core biopsies for routine histopathological evaluation?
Which type of bone marrow sample is BEST suited for evaluating the overall cellularity of the marrow?
Which type of bone marrow sample is BEST suited for evaluating the overall cellularity of the marrow?
During bone marrow aspiration, what is the PRIMARY purpose of using a stylet within the bone marrow needle?
During bone marrow aspiration, what is the PRIMARY purpose of using a stylet within the bone marrow needle?
Following bone marrow aspiration, why is it recommended to screen the slides in-house before submitting them to a pathologist?
Following bone marrow aspiration, why is it recommended to screen the slides in-house before submitting them to a pathologist?
In an adult dog, approximately what percentage of hematopoietic cells is considered normal in bone marrow spicules?
In an adult dog, approximately what percentage of hematopoietic cells is considered normal in bone marrow spicules?
What is the MOST likely interpretation of a bone marrow aspirate described as 'hypocellular'?
What is the MOST likely interpretation of a bone marrow aspirate described as 'hypocellular'?
In bone marrow evaluation, what is the normal expected trend in nuclear lobation of granulocytic cells as they mature?
In bone marrow evaluation, what is the normal expected trend in nuclear lobation of granulocytic cells as they mature?
What is the typical myeloid to erythroid (M:E) ratio range observed in bone marrow aspirates from dogs and cats?
What is the typical myeloid to erythroid (M:E) ratio range observed in bone marrow aspirates from dogs and cats?
In which species is a finding of very low numbers of granulocyte precursors in the bone marrow considered a normal physiological characteristic?
In which species is a finding of very low numbers of granulocyte precursors in the bone marrow considered a normal physiological characteristic?
What does a 'left shift' in myeloid maturation in bone marrow evaluation MOST likely indicate?
What does a 'left shift' in myeloid maturation in bone marrow evaluation MOST likely indicate?
Which of the following is LEAST likely to cause a hypocellular bone marrow?
Which of the following is LEAST likely to cause a hypocellular bone marrow?
In bone marrow aspirates stained with Romanowsky stain, what color change is observed in megakaryocytes as they mature?
In bone marrow aspirates stained with Romanowsky stain, what color change is observed in megakaryocytes as they mature?
For which of the following clinical scenarios is bone marrow evaluation LEAST indicated?
For which of the following clinical scenarios is bone marrow evaluation LEAST indicated?
What is myelophthisis BEST defined as in the context of bone marrow disorders?
What is myelophthisis BEST defined as in the context of bone marrow disorders?
In dogs, finding more than 10 plasma cells per 10x field in a bone marrow aspirate is MOST suggestive of:
In dogs, finding more than 10 plasma cells per 10x field in a bone marrow aspirate is MOST suggestive of:
Which of the following CBC findings would be the STRONGEST indication to perform a bone marrow evaluation?
Which of the following CBC findings would be the STRONGEST indication to perform a bone marrow evaluation?
In a bone marrow aspirate from a cat with a myeloid to erythroid (M:E) ratio of 5:1, assuming normal erythroid morphology, what is the MOST likely interpretation?
In a bone marrow aspirate from a cat with a myeloid to erythroid (M:E) ratio of 5:1, assuming normal erythroid morphology, what is the MOST likely interpretation?
Which of the following is considered a potential cause of aplastic anemia in animals?
Which of the following is considered a potential cause of aplastic anemia in animals?
In which animal species is iron storage in bone marrow macrophages considered a normal and prominent finding?
In which animal species is iron storage in bone marrow macrophages considered a normal and prominent finding?
What is the MOST appropriate first step after obtaining a bone marrow aspirate sample to ensure optimal cytologic evaluation?
What is the MOST appropriate first step after obtaining a bone marrow aspirate sample to ensure optimal cytologic evaluation?
Which bone marrow collection site carries the HIGHEST risk of penetrating the thoracic cavity in small animals?
Which bone marrow collection site carries the HIGHEST risk of penetrating the thoracic cavity in small animals?
Why might bone marrow samples from older animals be less representative of overall hematopoietic status compared to younger animals when collected from certain sites?
Why might bone marrow samples from older animals be less representative of overall hematopoietic status compared to younger animals when collected from certain sites?
In a dog with a normal PCV, leukocytosis, and increased M:E ratio in bone marrow, which of the following bone marrow terminologies BEST describes the myeloid series?
In a dog with a normal PCV, leukocytosis, and increased M:E ratio in bone marrow, which of the following bone marrow terminologies BEST describes the myeloid series?
In a dog with non-regenerative anemia and normal leukogram, if bone marrow evaluation reveals erythroid hypoplasia and normal granulopoiesis, what is the MOST likely interpretation regarding the anemia?
In a dog with non-regenerative anemia and normal leukogram, if bone marrow evaluation reveals erythroid hypoplasia and normal granulopoiesis, what is the MOST likely interpretation regarding the anemia?
For routine histopathological evaluation of a bone marrow core biopsy, which stain is MOST commonly used?
For routine histopathological evaluation of a bone marrow core biopsy, which stain is MOST commonly used?
What is the general term for hematopoietic cells that exhibit increasing segmentation of their nuclei as they mature, particularly referring to neutrophils?
What is the general term for hematopoietic cells that exhibit increasing segmentation of their nuclei as they mature, particularly referring to neutrophils?
In a bone marrow aspirate, what finding is MOST suggestive of myelodysplastic syndrome (MDS) rather than acute leukemia?
In a bone marrow aspirate, what finding is MOST suggestive of myelodysplastic syndrome (MDS) rather than acute leukemia?
Which of the following is LEAST likely to be an indication for bone marrow aspirate in a dog with regenerative anemia?
Which of the following is LEAST likely to be an indication for bone marrow aspirate in a dog with regenerative anemia?
If a bone marrow aspirate smear appears overly smudged with poor cellular morphology, what is the MOST likely technical error during preparation?
If a bone marrow aspirate smear appears overly smudged with poor cellular morphology, what is the MOST likely technical error during preparation?
In large animals, why is 'strong musculature' of the iliac crest a relevant consideration during bone marrow collection from this site?
In large animals, why is 'strong musculature' of the iliac crest a relevant consideration during bone marrow collection from this site?
Which of the following is the MOST accurate method to quantitatively assess bone marrow cellularity?
Which of the following is the MOST accurate method to quantitatively assess bone marrow cellularity?
A dog has a PCV of 39%, WBC of 25,800/µL, Segs of 20,000/µL, and Bands of 3,000/µL. Based on these CBC findings, what can be INFERRED about its bone marrow?
A dog has a PCV of 39%, WBC of 25,800/µL, Segs of 20,000/µL, and Bands of 3,000/µL. Based on these CBC findings, what can be INFERRED about its bone marrow?
A bone marrow evaluation reveals hypercellular spicules with increased Megakaryocytes and M:E Ratio 1:1 in a dog with hematuria. Which hematologic problem is MOST expected?
A bone marrow evaluation reveals hypercellular spicules with increased Megakaryocytes and M:E Ratio 1:1 in a dog with hematuria. Which hematologic problem is MOST expected?
In cases of suspected myelodysplasia, what is the TYPICAL percentage range of blasts found in the bone marrow that would be characteristic, but below the threshold for acute leukemia?
In cases of suspected myelodysplasia, what is the TYPICAL percentage range of blasts found in the bone marrow that would be characteristic, but below the threshold for acute leukemia?
True or False: Bone marrow findings can be interpreted without a current CBC for a more complete clinical picture.
True or False: Bone marrow findings can be interpreted without a current CBC for a more complete clinical picture.
Which of the following best describes the expected bone marrow findings in a case of immune-mediated hemolytic anemia (IMHA) with a regenerative response?
Which of the following best describes the expected bone marrow findings in a case of immune-mediated hemolytic anemia (IMHA) with a regenerative response?
What is the MOST likely cause of a nonregenerative anemia with a normal leukogram and normal platelet count?
What is the MOST likely cause of a nonregenerative anemia with a normal leukogram and normal platelet count?
Which of the following is the LEAST ideal location for bone marrow aspirate in small animals due to issues with sample representativeness?
Which of the following is the LEAST ideal location for bone marrow aspirate in small animals due to issues with sample representativeness?
What is the MOST accurate definition of 'aplastic anemia'?
What is the MOST accurate definition of 'aplastic anemia'?
Which type of bone marrow sample provides the BEST overall estimate of cellularity?
Which type of bone marrow sample provides the BEST overall estimate of cellularity?
What is the PRIMARY purpose of the stylet in a bone marrow aspiration needle?
What is the PRIMARY purpose of the stylet in a bone marrow aspiration needle?
Following bone marrow aspiration, what is the MOST important reason to examine the slides in-house before sending them to a pathologist?
Following bone marrow aspiration, what is the MOST important reason to examine the slides in-house before sending them to a pathologist?
In a healthy adult dog, what is the approximate normal percentage of hematopoietic cells observed in bone marrow spicules?
In a healthy adult dog, what is the approximate normal percentage of hematopoietic cells observed in bone marrow spicules?
What does a bone marrow aspirate described as 'hypocellular' suggest?
What does a bone marrow aspirate described as 'hypocellular' suggest?
For granulocytic cells, what is the expected change in nuclear lobation as they mature within the bone marrow?
For granulocytic cells, what is the expected change in nuclear lobation as they mature within the bone marrow?
What is the typical myeloid to erythroid (M:E) ratio range expected in healthy dogs and cats?
What is the typical myeloid to erythroid (M:E) ratio range expected in healthy dogs and cats?
In which species is a finding of very low numbers of granulocyte precursors in the bone marrow considered normal?
In which species is a finding of very low numbers of granulocyte precursors in the bone marrow considered normal?
In bone marrow evaluation, what does a 'left shift' in myeloid maturation indicate?
In bone marrow evaluation, what does a 'left shift' in myeloid maturation indicate?
Which factor is LEAST likely to cause a hypocellular bone marrow?
Which factor is LEAST likely to cause a hypocellular bone marrow?
For which clinical scenario is bone marrow evaluation LEAST indicated?
For which clinical scenario is bone marrow evaluation LEAST indicated?
In the context of bone marrow disorders, what does myelophthisis refer to?
In the context of bone marrow disorders, what does myelophthisis refer to?
In dogs, what does a bone marrow aspirate finding of >10 plasma cells per 10x field MOST likely suggest?
In dogs, what does a bone marrow aspirate finding of >10 plasma cells per 10x field MOST likely suggest?
Which of the following complete blood count (CBC) findings would be the STRONGEST indication for a bone marrow evaluation?
Which of the following complete blood count (CBC) findings would be the STRONGEST indication for a bone marrow evaluation?
A bone marrow aspirate from a cat has a myeloid to erythroid (M:E) ratio of 5:1. Assuming normal erythroid morphology, what is the MOST likely interpretation?
A bone marrow aspirate from a cat has a myeloid to erythroid (M:E) ratio of 5:1. Assuming normal erythroid morphology, what is the MOST likely interpretation?
Which of the following is a potential cause of aplastic anemia in animals?
Which of the following is a potential cause of aplastic anemia in animals?
After obtaining a bone marrow aspirate sample, what is the FIRST step to ensure optimal cytologic evaluation?
After obtaining a bone marrow aspirate sample, what is the FIRST step to ensure optimal cytologic evaluation?
What bone marrow collection site has the HIGHEST risk of accidental penetration into the thoracic cavity in small animals?
What bone marrow collection site has the HIGHEST risk of accidental penetration into the thoracic cavity in small animals?
Why might bone marrow samples from older animals be less representative compared to younger animals when collected from certain sites?
Why might bone marrow samples from older animals be less representative compared to younger animals when collected from certain sites?
In a dog with a normal PCV, leukocytosis, and increased M:E ratio in bone marrow, which term best describes the myeloid series?
In a dog with a normal PCV, leukocytosis, and increased M:E ratio in bone marrow, which term best describes the myeloid series?
In a dog with non-regenerative anemia and a normal leukogram, if bone marrow evaluation reveals erythroid hypoplasia and normal granulopoiesis, what is the MOST appropriate interpretation?
In a dog with non-regenerative anemia and a normal leukogram, if bone marrow evaluation reveals erythroid hypoplasia and normal granulopoiesis, what is the MOST appropriate interpretation?
Which statement is MOST accurate?
Which statement is MOST accurate?
What cellular feature is BEST evaluated using a bone marrow aspirate?
What cellular feature is BEST evaluated using a bone marrow aspirate?
Which sample collection method is considered optimal for specifically assessing bone marrow cellularity?
Which sample collection method is considered optimal for specifically assessing bone marrow cellularity?
From which location would you MOST likely obtain bone marrow samples in small animals?
From which location would you MOST likely obtain bone marrow samples in small animals?
What is the PRIMARY function of the stylet during bone marrow aspiration?
What is the PRIMARY function of the stylet during bone marrow aspiration?
Why is it important to screen bone marrow aspirate slides in-house immediately after collection?
Why is it important to screen bone marrow aspirate slides in-house immediately after collection?
In an adult dog, what percentage range of hematopoietic cells within bone marrow spicules is generally considered normal?
In an adult dog, what percentage range of hematopoietic cells within bone marrow spicules is generally considered normal?
As granulocytic cells mature, what change is expected in their nuclear morphology?
As granulocytic cells mature, what change is expected in their nuclear morphology?
What is the typical myeloid to erythroid (M:E) ratio range in bone marrow aspirates from healthy dogs and cats?
What is the typical myeloid to erythroid (M:E) ratio range in bone marrow aspirates from healthy dogs and cats?
In which species is a finding of very low numbers of granulocyte precursors in the bone marrow considered a normal physiological variation?
In which species is a finding of very low numbers of granulocyte precursors in the bone marrow considered a normal physiological variation?
A 'left shift' in myeloid maturation suggests what?
A 'left shift' in myeloid maturation suggests what?
Which is LEAST likely to cause a hypocellular bone marrow?
Which is LEAST likely to cause a hypocellular bone marrow?
Within the context of bone marrow disorders, what does the term 'myelophthisis' MOST accurately describe?
Within the context of bone marrow disorders, what does the term 'myelophthisis' MOST accurately describe?
In dogs, a bone marrow aspirate with >10 plasma cells per 10x field is MOST indicative of what?
In dogs, a bone marrow aspirate with >10 plasma cells per 10x field is MOST indicative of what?
Which CBC finding makes bone marrow evaluation MOST necessary?
Which CBC finding makes bone marrow evaluation MOST necessary?
How should you interpret a bone marrow aspirate from a cat with a myeloid to erythroid (M:E) ratio of 5:1 and normal erythroid morphology?
How should you interpret a bone marrow aspirate from a cat with a myeloid to erythroid (M:E) ratio of 5:1 and normal erythroid morphology?
Which options are potential causes of aplastic anemia in animals?
Which options are potential causes of aplastic anemia in animals?
What is the FIRST step after obtaining a bone marrow aspirate to ensure optimal cytologic evaluation?
What is the FIRST step after obtaining a bone marrow aspirate to ensure optimal cytologic evaluation?
Which of the listed collection sites is associated with the HIGHEST risk of penetrating the thoracic cavity in small animals?
Which of the listed collection sites is associated with the HIGHEST risk of penetrating the thoracic cavity in small animals?
Flashcards
Aspirate Advantages
Aspirate Advantages
Superior cell detail & better detection of small tumor cell numbers.
Core Biopsy Advantages
Core Biopsy Advantages
Better estimate of cellularity
Small Animal Collection Sites
Small Animal Collection Sites
Iliac crest, proximal femur, proximal humerus, sternum
Bone Marrow Biopsy Technique
Bone Marrow Biopsy Technique
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Marrow Evaluation Components
Marrow Evaluation Components
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Bone Marrow Cellularity
Bone Marrow Cellularity
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Hypocellular Marrow
Hypocellular Marrow
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Hypercellular Marrow
Hypercellular Marrow
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Bone Marrow Lymphocytes
Bone Marrow Lymphocytes
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Iron Pigments
Iron Pigments
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Bone Marrow Evaluation Indications
Bone Marrow Evaluation Indications
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Infectious Causes of BME
Infectious Causes of BME
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When add Core Biopsy?
When add Core Biopsy?
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Underlying cause
Underlying cause
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Myelodysplasia
Myelodysplasia
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Bone Marrow Aspirate
Bone Marrow Aspirate
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Core Biopsy
Core Biopsy
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Bone Marrow Sampling Technique
Bone Marrow Sampling Technique
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Bone Marrow Sample Handling
Bone Marrow Sample Handling
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Slide Screening Importance
Slide Screening Importance
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Megakaryocyte Appearance
Megakaryocyte Appearance
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Estimating Bone Marrow Cellularity
Estimating Bone Marrow Cellularity
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Detailed Cell Type Evaluation
Detailed Cell Type Evaluation
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Myeloid to Erythroid (M:E) Ratio
Myeloid to Erythroid (M:E) Ratio
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High M:E Ratio Implication
High M:E Ratio Implication
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Low M:E Ratio
Low M:E Ratio
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Left Shift
Left Shift
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Left Shift Cause
Left Shift Cause
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Normal M:E Ratio
Normal M:E Ratio
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Multiple Myeloma
Multiple Myeloma
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Elevated Plasma Cells
Elevated Plasma Cells
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Indications for Bone Marrow Evaluation
Indications for Bone Marrow Evaluation
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Myelopthesis
Myelopthesis
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Pancytopenia
Pancytopenia
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Myelofibrosis Diagnosis
Myelofibrosis Diagnosis
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Bone Marrow Response
Bone Marrow Response
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M:E Visual Aid
M:E Visual Aid
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Diagnostic Results
Diagnostic Results
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Inflammation for cause
Inflammation for cause
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Hematuria
Hematuria
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Blood Test result
Blood Test result
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Antibody On RBC
Antibody On RBC
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Inflammation time
Inflammation time
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Hemorrhage result
Hemorrhage result
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Aplastic Anemia Cause
Aplastic Anemia Cause
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Myelodysplasia Cause
Myelodysplasia Cause
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Morphology Check
Morphology Check
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Study Notes
Bone Marrow Evaluation - Techniques and Procedures
- Bone marrow evaluation involves aspiration and/or biopsy to analyze marrow components, aiding in diagnosing various hematological and systemic conditions.
Aspirate vs. Core Biopsy
- Aspirates provide superior cellular details, making it easier to count cells, identify cell types, observe cell morphology, and detect small numbers of tumor cells.
- Assessing overall cellularity is difficult with aspirates
- Core biopsies provide a better estimate of overall cellularity
- Core biopsies make individual cell identification harder
- Performing both aspirates and core biopsies as a combo is common for comprehensive evaluation.
Small Animal Collection Sites
- Common collection sites include the iliac crest, proximal femur, proximal humerus, and sternum
- These sites allow for easy access to bone marrow in small animals.
- Proximal humerus is a frequently used site.
Collection Sites in Large Animals
- Collection sites in large animals are rib, sternum, iliac crest (tuber coxae), and humeral head.
- Iliac crest requires strong muscles for effective sampling.
- The humeral head is commonly used.
- When collecting from the rib or sternum, angle the needle to avoid puncturing the heart or other organs.
Bone Marrow Aspiration Procedure
- The procedure involves inserting a needle through a stab incision and rotating it until firmly seated in the bone.
- Remove the stylet, attach a syringe, and aspirate only 1-2 drops of marrow using minimal suction.
- Stain slides with Romanovsky stain
- Screen for cellularity through pieces of marrow called spicules, flakes, particles
- Aim for a lumpy sample with marrow particles, not just peripheral blood
- Marrow samples clot quickly, so prepare smears rapidly or use EDTA solution to buy time
- Screen the slides to verify sample adequacy before sending them to a pathologist.
Bone Marrow Biopsy
- A larger Jamshidi needle is used for bone marrow biopsies, and also has a stylet in the middle
- The needle is seated with the stylet in place, then the stylet is removed.
- After drilling further into trabecular bone, rock the needle back and forth to dislodge a piece of bone.
- The core is fixed in formalin and stained with H&E.
- The bone core is pushed out of the needle's back end using the stylet into formalin for fixation
Bone Marrow Interpretation
- Bone marrow samples should be examined by veterinary pathologists.
- The evaluation includes assessment of cellularity, presence of megakaryocytes, and the myeloid:erythroid ratio (M:E ratio).
- Additional aspects checked are morphologic features of precursors, presence of other cell types or organisms, and iron stores.
- Orderly and progressive maturation of RBCs and WBCs is also critical in bone marrow evaluation.
Bone Marrow Cellularity
- Cellularity assessment requires marrow particles and is best evaluated on core biopsies.
- In normal adult animals, hematopoietic cells constitute 25-50% of the marrow, with the rest being fat while in neonates hematopoietic cells can be up to 75% of the marrow.
- Assess cellularity by estimating the proportion of fat (white) to hematopoietic cells (blue) in marrow particles.
Hypocellular Marrow
- Hypocellular marrow aspirates look like blood or fatty particles with lacy fibrovascular stroma.
- Viral infections, toxicities, and immune-mediated diseases can cause hypocellularity.
Hypercellular Marrow
- Hypercellular marrow is characterised by hyperplasia of normal cells, myeloproliferative disease, or neoplasia.
- Hypercellular marrow consists of particles with minimal fat, indicating a high concentration of hematopoietic cells
Megakaryocytes
- Megakaryocytes are large cells, and early precursors are basophilic.
- Mature megakaryocytes are more eosinophilic with more cytoplasm and increased nuclear lobation.
- A couple to around 10 megakaryocytes per 10x field, almost always associated with the spicules, is normal
- Hyperplasia is defined as >10 cells per 10x field.
Cell Evaluation
- To evaluate cells move away from the spicules toward thinner areas where cells are spread-out and well-stained for identification.
Erythroid Cells
- These cells have intensely basophilic cytoplasm, no granules, perfectly round nuclei, and dense appearance.
- Immature red cells have dark purple chromatin, distinguishing them from lymphocytes, which have more pinky-purple chromatin.
Granulopoiesis
- Primary and lineage-specific granules are present in granulopoiesis.
- Cells are lightly basophilic, with chromatin that is finely stippled and then increasingly condensed.
Myeloid:Erythroid Ratio (M:E)
- The M:E ratio is the ratio of granulocytes to nucleated erythrocytes.
- Myeloid cells include granulocytes and monocyte precursors, excluding lymphocytes, plasma cells, and macrophages.
- Normal values vary by species: 0.5:1-3.5:1 in cats and dogs, 0.5:1-2.0:1 in horses, and 0.5:1-0.6:1 in cows.
- Most of the time the ratio is one-to-one or two-to-one in dogs and cats.
- Horses tend to be 0.5-to-one, maybe one-to-one.
- Interpretation requires current CBC and marrow spicule cellularity estimate, varying with cellularity.
- Low M:E ratio in cows indicates fewer granulocyte precursors and more erythroid cells.
Erythroid & Myeloid Maturation
- Maturation is normal if it is progressive, with mature cells being most numerous (pyramid effect).
- Maturation is "left shifted" with increased proportion of early precursors.
- Left shifted maturation can result from the increased consumption and therefore need for mature red blood cells.
- Common causes of this are inflammatory conditions
- Anemia may also cause left shifted maturation
- Defects in cell development such as maturation arrest and dysplasia are causes for left shifted maturation
- In ruminants, left shift is frequently observed during acute inflammation due to limited reserve granulocytes.
Lymphocytes
- Normal marrow contains <10% lymphocytes in dogs and <20% in cats.
- Increased small lymphocytes may indicate antigenic stimulation or immune-mediated disease.
- Increased medium to large lymphocytes indicates neoplasia.
Plasma Cells
- Normal marrow contains <2% plasma cells.
- Increased numbers may indicate antigenic stimulation, immune-mediated disease, Ehrlichia, or multiple myeloma (>10% of nucleated cells).
Macrophages
- Normal marrow contains <1% macrophages.
- Increased macrophages can indicate immune-mediated destruction of hematopoietic cells, infectious disease (Leishmania, Histoplasmosis), or histiocytic sarcoma.
Iron Pigments (Hemosiderin)
- Prominent in dogs and primates, visible at 10x in spicules.
- They appear as chunky, yellow-gold to brown pigment.
- Marrow estimates of iron status are not generally reliable
Indications for Bone Marrow Evaluation
- Atypical cells in circulation
- Myeloid or lymphoid leukemia
- Lymphoma
- Unexplained hyperglobulinemia
- Multiple myeloma
- Some B cell lymphomas
- Unexplained hypercalcemia
- T-cell lymphoma
- Multiple myeloma
- Identification of infectious agents
- Histoplasma
- Leishmania
- Bone marrow is considered if the animal has a travel history of coming from the Midwest and the following is suspected: Histoplasma (round oval yeast with a thick cell wall in macrophages)
- Bone marrow is considered if the animal has a travel history that the animal came from Mediterranean regions, so southern France, Turkey, or Central America and the following is suspected: Leishmania (little round oval structures that have kind of a, to me, it's either V-shaped, or you might think of it as L-shaped, a little L-shaped structure in the middle.)
- Unexplained Prolonged Cytopenia
- Nonregenerative anemia and rule out extra marrow causes.
- Neutropenia of thrombocytopenia
- Pancytopenia, rule out inflammation or endotoxemia.
- A bone marrow evaluation is typically performed in animals with unexplained abnormalities in their CBC, except when looking for Leishmania
- Bone marrow evaluation is often avoided if the cause of the condition is already explainable through the animal's history or other testing
- Bone marrow evaluation can be triggered by high globulin levels, which can be caused by multiple myeloma or some forms of lymphoma
- If lymphoma cannot be found elsewhere in the body, bone marrow can be a last resort to diagnose the condition
- Bone marrow evaluation is considered for non-regenerative anemia, neutropenia, or pancytopenia, especially in the absence of inflammation
Additional Indications for A Core Biopsy
- A core biopsy is needed in cases of Cytopenia/pancytopenia rule out myelofibrosis.
- The biopsy provides the most accurate assessment of cellularity.
- A core biopsy is essential in pancytopenic animals to rule out aplastic anemia or myelofibrosis.
Interpretation of Bone Marrow Samples
- Interpretation of marrow cytology requires a current CBC, ideally within 24-48 hours of the bone marrow sample.
- Evaluation helps determine if bone marrow response is appropriate and if marrow findings explain the abnormalities.
- Bone marrow evaluation seeks to determine if the bone marrow's response is appropriate or if marrow findings explain abnormalities in the CBC
- Bone marrow interpretation must consider: overall cellularity and M:E ratio
Increased M:E Ratio
- Increased myeloid:erythroid ratio can occur with leukocytosis and a normal red cell line.
- Also an increase in M:E ration can also occur with a normal leukogram but and nonregenerative anemia
- An third case can be when there is leukocytosis and nonregenerative anemia
Decreased M:E Ratio
- Decreased M:E ratio can occur with leukopenia with normal PCV.
- Normal leukogram regenerative anemia.
- Leukopenia with regenerative anemia, or degenerative left shift with normal PCV can also cause a decreased M:E ratio.
Clinical Cases and Considerations
- Visual aids such as pretzels were used to represent granulocytes (white), erythroid cells (red), and megakaryocytes
Dog A
- Findings: Slightly increased marrow cellularity (60-80%), adequate megakaryocytes, M:E ratio 3.5:1 (1.0-2.0:1), normal myeloid and erythroid morphology/maturation.
- CBC: Inflammatory leukogram.
- Interpretation: Hypercellular spicules, high M:E ratio, normal red cells, granulocytic hyperplasia, appropriate response by the bone marrow
Dog B
- Findings: Slightly decreased marrow cellularity (30-40%), adequate megakaryocytes, M:E ratio 3.5:1 (1.0-2.0:1), normal myeloid and erythroid morphology/maturation.
- CBC: Anemia.
- Interpretation: normal granulocytes, megakaryocytes and erythroid hypoplasia. , marrow is the problem and it's not responding normally
Kitten
- History: 5-month-old kitten with nasal discharge and fleas.
- CBC: Neutrophilic leukocytosis with mild toxic change, mild normocytic normochromic anemia, no reticulocytes, adequate platelets.
- Bone Marrow: Average cellularity (~50%), adequate megakaryocytes, M:E ratio 8.0:1 (1.0-2.0:1), normal myeloid and erythroid morphology/maturation.
- Interpretation: granulocytic hyperplasia, erythroid, and anemia of inflammation is contributing, but blood loss due to fleas is probably on top.
Cocker Spaniel
- History: 5-year-old FS Cocker Spaniel with hematuria.
- CBC: Anemia, icteric plasma, inflammatory leukogram, thrombocytopenia.
- Bone Marrow: Hypercellular spicules (80-95%), increased megakaryocytes, M:E ratio 1:1 (1.0-2.0:1), normal myeloid and erythroid morphology/maturation, 4% plasma cells.
- Hyperplasia of all three lineages, increase megakaryopoiesis and results in a inflammatory response, resulting in hemorrhage
Steer
- History: Found dead in pasture near wooded area with poor forage, blood crusted nostrils, black/tarry feces, and hemorrhage in multiple organs.
- Marrow findings: <25% hematopoietic tissue, indicating aplastic anemia.
- Bracken Fern Toxicity: Whole plant is toxic. Chronic poisoning leads to hemorrhagic cystitis and bladder tumors. Acute ingestion leads to marrow suppression, causing coagulopathy and septicemic crisis.
- Hemorrhage is due to thrombocytopenia, other cows instead of dying of hemorrhage will die of a septic process because they don't have neutrophils to fight off bacteria.
Myelodysplasia
- Clonal disorder characterized by INEFFECTIVE HEMATOPOIESIS
- A genetic mutation prevents differentiation
- It has been described as a pre-leukemic conditiions, transforming into AML often.
- Abnormality is in early precursors, but ability to mature is retained
- Presentation is normally below <20% blasts and a Marrow that is normo- to hypercellular-
- It presents with peripheral cytopenias, dysplastic hematopoietic cells, an Increased Rate of cell division and Cell drop-out via apoptosis than normal.
- Marrow Trying its best, they start to differentiate, and then they hit a wall, and they can't get all the way through.
- The abnormal morphology in the white cells and the red cells is sometimes subtle
- An example is of what you might see, so this is a megaloblastoid red cell, so here's a normal red cell, and here's a normal red cell, this is ginormous red cell.
- Asynchronous maturation, where the cytoplasm is maturing faster than the nucleus could occur
- Expect to see a left shift, and then you look for dysplastic changes in the two lineages, dysplasia
- They often will have an abnormal morphology.
- Example of megaloblastoid red cell.
- Cytoplasm maturing faster than the nucleus example is asynchronous maturation
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