Welcome to Part 43 of our Free ASCP MLS Exam Practice Questions series. In this section, we focus on Bone Marrow Examination and Disorders, a vital area of hematology that provides key insights into hematopoiesis, malignant hematologic diseases, and bone marrow failure syndromes.
🔹 Topics Covered in This Part
- Bone marrow anatomy and physiology
- Bone marrow aspiration and biopsy techniques
- Normal bone marrow cellularity and differential counts
- Hypocellular marrow (aplastic anemia, marrow suppression)
- Hypercellular marrow (leukemias, myeloproliferative neoplasms, myelodysplastic syndromes)
- Role of cytogenetics, flow cytometry, and molecular testing in bone marrow diagnosis
60 MCQs (3521- 3580):
📘 How to Use These Practice Questions
- This section emphasizes the diagnostic value and interpretation of bone marrow findings.
- Question numbering continues from the previous set — starting at Question 3521.
- Answer keys with explanations will be provided at the end of the question set for deeper understanding.
- The primary site of hematopoiesis in adults is:
a) Liver
b) Spleen
c) Bone marrow
d) Thymus - Which bone is most commonly used for adult bone marrow aspiration?
a) Sternum
b) Tibia
c) Iliac crest
d) Femur - In children, bone marrow aspiration is often performed from the:
a) Sternum
b) Tibia
c) Radius
d) Ulna - A “dry tap” during bone marrow aspiration is most commonly associated with:
a) Iron deficiency anemia
b) Aplastic anemia or myelofibrosis
c) Megaloblastic anemia
d) Hemolytic anemia - Normal bone marrow cellularity in adults is approximately:
a) 10%
b) 30–70%
c) 90%
d) 100% - Which stain is used to demonstrate iron stores in bone marrow?
a) PAS stain
b) Prussian blue stain
c) Wright–Giemsa stain
d) Sudan black stain - Which bone marrow finding is characteristic of aplastic anemia?
a) Hypercellular marrow
b) Hypocellular marrow with fatty replacement
c) Normal cellularity
d) Increased blasts - Increased blasts (>20%) in bone marrow is diagnostic of:
a) Leukemoid reaction
b) Leukemia (acute)
c) Aplastic anemia
d) Myelodysplasia only - Ring sideroblasts in bone marrow are seen in:
a) Iron deficiency anemia
b) Sideroblastic anemia
c) Thalassemia
d) Pernicious anemia - Myelofibrosis is characterized by:
a) Increased bone marrow cellularity
b) Bone marrow fibrosis and extramedullary hematopoiesis
c) Increased iron stores
d) Pure erythroid hyperplasia - Which of the following is a feature of megaloblastic bone marrow?
a) Nuclear–cytoplasmic asynchrony
b) Hypocellularity
c) Abundant iron stores
d) Predominance of lymphoblasts - Which cell type is increased in multiple myeloma bone marrow?
a) Lymphoblasts
b) Plasma cells
c) Erythroblasts
d) Myeloblasts - Which bone marrow disorder shows “dry tap” and tear-drop cells in blood smear?
a) Polycythemia vera
b) Myelofibrosis
c) Aplastic anemia
d) Leukemoid reaction - Which condition shows hypocellular bone marrow and pancytopenia?
a) Aplastic anemia
b) Iron deficiency anemia
c) Thalassemia minor
d) CML - Which test is used to assess the myeloid-to-erythroid (M:E) ratio in bone marrow?
a) Flow cytometry
b) Morphologic differential count
c) Hemoglobin electrophoresis
d) Reticulocyte count - Normal M:E ratio in bone marrow is approximately:
a) 1:1
b) 2–4:1
c) 10:1
d) 20:1 - In which disorder is bone marrow packed with small mature lymphocytes?
a) ALL
b) CLL
c) AML
d) Multiple myeloma - Which bone marrow change is typical in hemolytic anemia?
a) Increased erythroid precursors
b) Decreased erythroid activity
c) Fatty replacement
d) Fibrosis - Bone marrow biopsy in polycythemia vera usually shows:
a) Hypocellularity
b) Hypercellularity with increased RBC precursors
c) Increased lymphocytes only
d) Increased blasts only - Dyserythropoiesis with nuclear abnormalities is a hallmark of:
a) Megaloblastic anemia
b) Myelodysplastic syndrome (MDS)
c) Sickle cell anemia
d) Leukemoid reaction - Bone marrow involvement with Reed–Sternberg cells is typical of:
a) Hodgkin lymphoma
b) Non-Hodgkin lymphoma
c) Multiple myeloma
d) AML - Gaucher cells in bone marrow contain:
a) DNA remnants
b) Glucocerebroside-filled macrophages
c) Iron deposits
d) Hemoglobin crystals - Sea-blue histiocytes in bone marrow are associated with:
a) Lipid storage disorders
b) Megaloblastic anemia
c) Iron deficiency
d) Aplastic anemia - In multiple myeloma, the peripheral smear often shows:
a) Rouleaux formation
b) Target cells
c) Howell–Jolly bodies
d) Bite cells - Which disorder shows increased megakaryocytes in bone marrow?
a) Essential thrombocythemia
b) Aplastic anemia
c) Iron deficiency anemia
d) Hemophilia A - The primary diagnostic test for hairy cell leukemia involves:
a) Bone marrow biopsy with “dry tap”
b) Reticulocyte count
c) Hemoglobin electrophoresis
d) Coombs test - Which finding is common in bone marrow of patients with CML?
a) Increased blasts >20%
b) Granulocytic hyperplasia with left shift
c) Fatty replacement
d) Pure erythroid hyperplasia - Myelodysplastic syndromes (MDS) are best described as:
a) Purely erythroid disorders
b) Clonal stem cell disorders with dysplasia and cytopenias
c) Reactive conditions
d) Autoimmune marrow suppression - Which bone marrow feature is associated with parvovirus B19 infection?
a) Hypercellularity
b) Giant pronormoblasts
c) Increased blasts
d) Increased megakaryocytes - Which procedure is most useful for detecting marrow fibrosis?
a) Aspirate smear
b) Core biopsy with reticulin stain
c) Flow cytometry
d) Peripheral smear - In a normal adult bone marrow aspirate, what is the most common granulocyte found?
a) Myeloblast
b) Promyelocyte
c) Metamyelocyte
d) Segmented Neutrophil - What is the typical myeloid to erythroid (M:E) ratio in a normal adult bone marrow?
a) 1:1
b) 1:3
c) 3:1
d) 10:1 - Which of the following is the largest cell normally found in the bone marrow?
a) Osteoblast
b) Histiocyte
c) Megakaryocyte
d) Mast Cell - In an uncomplicated case of severe iron deficiency anemia, what would bone marrow iron stores (as assessed by Prussian blue stain) typically show?
a) Markedly increased
b) Normal
c) Absent
d) Ringed sideroblasts - A bone marrow examination revealing 30% proerythroblasts and >80% erythroid precursors is most characteristic of:
a) Myelodysplastic Syndrome (MDS)
b) Acute Myeloid Leukemia (AML) with minimal differentiation
c) Acute Erythroid Leukemia
d) Aplastic Anemia - The replacement of normal marrow precursor cells by an accumulation of more than 20% blasts is a hallmark of:
a) Chronic Lymphocytic Leukemia (CLL)
b) Myelodysplastic Syndromes (MDS)
c) Acute Myeloid Leukemia (AML)
d) Polycythemia Vera (PV) - Which of the following is a characteristic bone marrow finding in primary myelofibrosis?
a) Pannyelosis
b) Marrow fibrosis
c) Ringed sideroblasts
d) Decreased megakaryocytes - Giant, vacuolated, multinucleated erythroid precursors are a characteristic dysplastic finding in which of the following?
a) Chronic Myelogenous Leukemia (CML)
b) Primary Myelofibrosis
c) Erythroleukemia
d) Acute Lymphoblastic Leukemia (ALL) - A hypercellular bone marrow with a high myeloid to erythroid (M:E) ratio is most commonly due to:
a) Lymphoid hyperplasia
b) Granulocytic hyperplasia
c) Normoblastic hyperplasia
d) Myeloid hypoplasia - The presence of ringed sideroblasts in the bone marrow, characterized by iron-laden mitochondria surrounding the nucleus, is indicative of:
a) Iron deficiency anemia
b) Anemia of chronic inflammation
c) Sideroblastic anemia
d) Thalassemia - In polycythemia vera, the bone marrow M:E ratio is usually:
a) Normal (approximately 3:1)
b) High (>10:1)
c) Low (<2:1)
d) Variable and unpredictable - What defines the MDS subgroup “Refractory Anemia with Ringed Sideroblasts” (RARS)?
a) >15% ringed sideroblasts with <5% blasts
b) >50% ringed sideroblasts with >20% blasts
c) <5% ringed sideroblasts with single lineage dysplasia
d) Presence of Auer rods with any number of ringed sideroblasts - A bone marrow that is hypercellular with 50% or more of the nucleated cells being erythroid precursors and a low M:E ratio is characteristic of:
a) Chronic Myelogenous Leukemia (CML)
b) Erythroleukemia
c) Aplastic Anemia
d) Essential Thrombocythemia - Which of the following bone marrow findings would favor a diagnosis of multiple myeloma over a reactive plasmacytosis?
a) Presence of occasional flame cells
b) Plasmacytic satellitesis
c) Sheets of immature plasma cells
d) Presence of Russell bodies - The Philadelphia chromosome, a translocation between chromosomes 9 and 22, is a classic cytogenetic finding in which bone marrow disorder?
a) Acute Promyelocytic Leukemia
b) Polycythemia Vera
c) Chronic Myelogenous Leukemia (CML)
d) Myelodysplastic Syndrome - A bone marrow biopsy showing “pannyelosis” (hyperplasia of all cell lines) is a characteristic feature of:
a) Aplastic Anemia
b) Myelodysplastic Syndrome (MDS)
c) Paroxysmal Nocturnal Hemoglobinuria (PNH)
d) Polycythemia Vera (PV) - Aplastic anemia is characterized by a bone marrow that is:
a) Hypercellular with increased blasts
b) Hypercellular with dysplastic changes
c) Hypocellular with fatty replacement
d) Normocellular with ringed sideroblasts - Which of the following is a WHO classification category for Myelodysplastic Syndrome (MDS)?
a) Chronic Myelomonocytic Leukemia (CMML)
b) Refractory Anemia with Excess Blasts (RAEB)
c) Essential Thrombocythemia (ET)
d) Juvenile Myelomonocytic Leukemia (JMML) - The presence of more than 15% ringed sideroblasts in the bone marrow is a key feature of which MDS subtype?
a) MDS with single lineage dysplasia
b) MDS with excess blasts
c) MDS with ringed sideroblasts
d) MDS with isolated del(5q) - Which cytogenetic abnormality is associated with a more stable clinical course in Myelodysplastic Syndromes (MDS)?
a) Monosomy 7
b) del(5q)
c) Trisomy 8
d) del(20q) - Foam cells with vacuolated cytoplasm containing sphingomyelin, seen in the bone marrow, are most characteristic of:
a) Gaucher Disease
b) Niemann-Pick Disease
c) Multiple Myeloma
d) Hairy Cell Leukemia - The bone marrow in Chronic Lymphocytic Leukemia (CLL) typically shows:
a) An increase in myeloblasts
b) An accumulation of small, mature-looking lymphocytes
c) An increase in megakaryocytes
d) A depletion of all cell lines - Which stain is considered the “gold standard” for assessing bone marrow iron stores?
a) Wright stain
b) Myeloperoxidase stain
c) Periodic acid-Schiff (PAS) stain
d) Prussian blue stain - In which of the following conditions is the bone marrow most likely to show a significant increase in eosinophil precursors?
a) AML with inv(16)
b) Chronic Lymphocytic Leukemia (CLL)
c) Iron deficiency anemia
d) Multiple Myeloma - An average of how many megakaryocytes should be found per low power field (10x objective) in a normal bone marrow aspirate?
a) 1-2
b) 5-10
c) 15-20
d) 25-30 - A bone marrow examination from a patient with suspected megaloblastic anemia would be expected to show:
a) Megaloblastoid erythropoiesis
b) Ringed sideroblasts
c) An absence of erythroid precursors
d) An increase in small, mature lymphocytes - The finding of “dwarf” or micromegakaryocytes in the bone marrow is a feature of:
a) Reactive thrombocytosis
b) Myeloproliferative neoplasms like Primary Myelofibrosis
c) Iron deficiency anemia
d) Vitamin B12 deficiency - Which of the following is a category in the WHO classification of myelodysplastic syndromes/myeloproliferative neoplasms (MDS/MPN)?
a) Acute Myelomonocytic Leukemia (AMML)
b) Chronic Myelogenous Leukemia (CML)
c) Refractory Anemia with Excess Blasts (RAEB)
d) Chronic Myelomonocytic Leukemia (CMML) - A bone marrow that is hypercellular with 95% of the cells being blasts, some with Auer rods, is diagnostic for:
a) Chronic Myelogenous Leukemia (CML)
b) Acute Myeloid Leukemia (AML)
c) Myelodysplastic Syndrome (MDS)
d) Aplastic Anemia - The presence of Auer rods in blast cells on a bone marrow smear is a feature of:
a) Acute Lymphoblastic Leukemia (ALL)
b) Chronic Lymphocytic Leukemia (CLL)
c) Acute Myeloid Leukemia (AML)
d) Hairy Cell Leukemia
📌 How to Use This Practice Set
- Answer each question before checking the key.
- Focus on why the correct answer is right and the others are wrong.
- Use this set as timed practice to simulate the real exam environment.
Answer Key
Answer Key:
- c) Bone marrow
- c) Iliac crest
- b) Tibia
- b) Aplastic anemia or myelofibrosis
- b) 30–70%
- b) Prussian blue stain
- b) Hypocellular marrow with fatty replacement
- b) Leukemia (acute)
- b) Sideroblastic anemia
- b) Bone marrow fibrosis and extramedullary hematopoiesis
- a) Nuclear–cytoplasmic asynchrony
- b) Plasma cells
- b) Myelofibrosis
- a) Aplastic anemia
- b) Morphologic differential count
- b) 2–4:1
- b) CLL
- a) Increased erythroid precursors
- b) Hypercellularity with increased RBC precursors
- b) Myelodysplastic syndrome (MDS)
- a) Hodgkin lymphoma
- b) Glucocerebroside-filled macrophages
- a) Lipid storage disorders
- a) Rouleaux formation
- a) Essential thrombocythemia
- a) Bone marrow biopsy with “dry tap”
- b) Granulocytic hyperplasia with left shift
- b) Clonal stem cell disorders with dysplasia and cytopenias
- b) Giant pronormoblasts
- b) Core biopsy with reticulin stain
- c) Metamyelocyte
- c) 3:1
- c) Megakaryocyte
- c) Absent
- c) Acute Erythroid Leukemia
- c) Acute Myeloid Leukemia (AML)
- b) Marrow fibrosis
- c) Erythroleukemia
- b) Granulocytic hyperplasia
- c) Sideroblastic anemia
- a) Normal (approximately 3:1)
- a) >15% ringed sideroblasts with <5% blasts
- b) Erythroleukemia
- c) Sheets of immature plasma cells
- c) Chronic Myelogenous Leukemia (CML)
- d) Polycythemia Vera (PV)
- c) Hypocellular with fatty replacement
- b) Refractory Anemia with Excess Blasts (RAEB)
- c) MDS with ringed sideroblasts
- b) del(5q)
- b) Niemann-Pick Disease
- b) An accumulation of small, mature-looking lymphocytes
- d) Prussian blue stain
- a) AML with inv(16)
- b) 5-10
- a) Megaloblastoid erythropoiesis
- b) Myeloproliferative neoplasms like Primary Myelofibrosis
- d) Chronic Myelomonocytic Leukemia (CMML)
- b) Acute Myeloid Leukemia (AML)
- c) Acute Myeloid Leukemia (AML)
Top 8 Medical Laboratory Scientist (MLS) Exams:
Top 8 Medical Laboratory Scientist (MLS) Exams that are recognized globally and can help professionals validate their credentials and enhance their career opportunities:
1. ASCP – American Society for Clinical Pathology (USA)
- Exam Name: MLS(ASCP)
- Eligibility: Bachelor’s degree with clinical laboratory experience.
- Global Recognition: High
- Purpose: Certifies Medical Laboratory Scientists in the United States and internationally.
2. AMT – American Medical Technologists (USA)
- Exam Name: MLT(AMT) or MT(AMT)
- Eligibility: Academic and/or work experience in medical laboratory technology.
- Global Recognition: Moderate
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3. AIMS – Australian Institute of Medical and Clinical Scientists
- Exam Name: AIMS Certification Exam
- Eligibility: Assessment of qualifications and work experience.
- Recognition: Required for practice in Australia.
- Purpose: Certification and registration in Australia.
4. CSMLS – Canadian Society for Medical Laboratory Science
- Exam Name: CSMLS General or Subject-specific Exams
- Eligibility: Graduation from a CSMLS-accredited program or equivalent.
- Recognition: Canada
- Purpose: Entry-to-practice certification in Canada.
5. IBMS – Institute of Biomedical Science (UK)
- Exam Name: Registration and Specialist Portfolio Assessment
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- Exam Name: DOH/HAAD License Exam
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- Recognition: UAE (Abu Dhabi)
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7. DHA – Dubai Health Authority (UAE)
- Exam Name: DHA License Exam for Medical Laboratory Technologists
- Eligibility: Relevant degree and experience.
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8. MOH – Ministry of Health (Gulf Countries like UAE, Saudi Arabia, Kuwait)
- Exam Name: MOH License Exam
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