Hematopathology — MCQs

Hematopathology Indian Medical PG Practice Questions and MCQs

Question 381: Hemophilia B is due to deficiency of which clotting factor?

A. Factor VIII
B. Factor VII
C. Factor IX (Correct Answer)
D. Factor X

Explanation: **Explanation:** **Hemophilia B**, also known as **Christmas Disease**, is an X-linked recessive bleeding disorder caused by a deficiency or dysfunction of **Clotting Factor IX**. Factor IX is a vitamin K-dependent serine protease essential for the intrinsic pathway of the coagulation cascade. Its deficiency impairs the generation of thrombin, leading to a failure of secondary hemostasis. **Analysis of Options:** * **Factor IX (Correct):** Deficiency leads to Hemophilia B. It is clinically indistinguishable from Hemophilia A but requires specific replacement with Factor IX concentrates. * **Factor VIII (Incorrect):** Deficiency of Factor VIII causes **Hemophilia A** (Classic Hemophilia), which is the most common type of hemophilia (80-85% of cases) [1]. * **Factor VII (Incorrect):** Deficiency leads to a rare autosomal recessive bleeding disorder. Since Factor VII is part of the extrinsic pathway, it is the only deficiency that prolongs PT while keeping aPTT normal. * **Factor X (Incorrect):** Deficiency is a rare autosomal recessive disorder affecting the common pathway, prolonging both PT and aPTT. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Both Hemophilia A and B are **X-linked recessive** (primarily affecting males) [1]. * **Lab Findings:** Characterized by **prolonged aPTT** with a **normal PT, normal bleeding time, and normal platelet count**. * **Mixing Study:** The prolonged aPTT corrects when the patient's plasma is mixed with normal pooled plasma (distinguishes deficiency from inhibitors). * **Clinical Feature:** The hallmark is **Hemarthrosis** (bleeding into joints, most commonly the knee) and muscle hematomas. * **Treatment:** Recombinant Factor IX; unlike Factor VIII, Factor IX has a longer half-life and smaller volume of distribution. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 670-671.

Question 382: Which of the following statements regarding umbilical cord banking is FALSE?

A. Blood is collected from the umbilical artery. (Correct Answer)
B. It is used for allogeneic stem cell transplant.
C. Transplantation can be done in people with different HLA matching.
D. Blood is preserved by cryopreservation.

Explanation: **Explanation:** **1. Why Option A is the Correct (False) Statement:** The primary source of cord blood for banking is the **umbilical vein**, not the artery [1]. After the baby is delivered and the cord is clamped, the umbilical vein is cannulated to collect the blood remaining in the placenta and the cord. This is because the vein is larger, more accessible, and contains a significant volume of hematopoietic stem cells (HSCs). **2. Analysis of Other Options:** * **Option B (Allogeneic transplant):** This is **true**. Cord blood is a rich source of HSCs used for allogeneic transplantation (donor to recipient) to treat hematological malignancies, bone marrow failure syndromes, and genetic metabolic disorders. * **Option C (HLA Matching):** This is **true**. One of the greatest advantages of cord blood is that it requires **less stringent HLA matching** compared to adult bone marrow. Because the neonatal immune cells are "immunologically naive," there is a lower risk and severity of Graft-versus-Host Disease (GvHD). * **Option D (Cryopreservation):** This is **true**. Collected units are processed to reduce volume and then stored in liquid nitrogen (usually at -196°C) using cryoprotectants like DMSO to maintain cell viability for years. **Clinical Pearls for NEET-PG:** * **HSC Source Comparison:** Cord blood has a higher concentration of progenitor cells than adult blood but contains a lower absolute total cell dose, which often limits its use to pediatric patients or smaller adults. * **Delayed Clamping:** Waiting 30–60 seconds before clamping the cord increases the infant's iron stores but may decrease the volume available for banking. * **GvHD:** Cord blood transplants have a significantly lower incidence of chronic GvHD compared to peripheral blood stem cell transplants. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Female Genital Tract, pp. 1038-1040.

Question 383: The type of non-Hodgkin's lymphoma with the highest rate of gastrointestinal system involvement is:

A. B cell chronic lymphocytic leukemia
B. Mantle cell lymphoma
C. Extranodal marginal zone B cell lymphoma of MALT type (Correct Answer)
D. Follicular lymphoma

Explanation: **Explanation:** **1. Why Option C is Correct:** Extranodal marginal zone B-cell lymphoma of MALT (Mucosa-Associated Lymphoid Tissue) type is, by definition, an extranodal lymphoma. The **Gastrointestinal (GI) tract is the most common site** for MALTomas, with the stomach being involved in approximately 85% of cases [1]. These lymphomas typically arise in the setting of chronic inflammation, most notably due to ***Helicobacter pylori* infection** [1]. The underlying concept is that chronic antigenic stimulation leads to the accumulation of lymphoid tissue in the gastric mucosa, which eventually undergoes malignant transformation [1]. **2. Why the Other Options are Incorrect:** * **Option A (B-CLL):** This is primarily a systemic disease involving the bone marrow, peripheral blood, and lymph nodes. While it can involve the GI tract in advanced stages, it is rarely the primary or most frequent site. * **Option B (Mantle Cell Lymphoma):** While MCL is famous for causing **Lymphomatous Polyposis** (multiple small nodules in the GI tract), its overall incidence and rate of primary GI involvement are lower than those of MALToma. * **Option D (Follicular Lymphoma):** This is a nodal lymphoma [2]. When it does occur in the GI tract, it most commonly involves the duodenum, but this is significantly less frequent than MALToma. **3. High-Yield NEET-PG Pearls:** * **Most common site of MALToma:** Stomach [1]. * **Key Association:** *H. pylori* (Stomach) [1], *Chlamydia psittaci* (Ocular adnexa), *Borrelia burgdorferi* (Skin). * **Cytogenetics:** **t(11;18)(q21;q21)** is the most common translocation in MALToma; its presence usually indicates resistance to *H. pylori* eradication therapy. * **Histology:** Characterized by **lymphoepithelial lesions** (invasion of mucosal glands by neoplastic B-cells). **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 356-357. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 561-562.

Question 384: Pancytopenia with a cellular bone marrow is seen in all of the following conditions except:

A. Paroxysmal nocturnal hemoglobinuria (PNH)
B. Megaloblastic anemia
C. Myelodysplastic syndrome
D. Dyskeratosis congenita (Correct Answer)

Explanation: **Explanation:** The core concept tested here is the distinction between **hypocellular** (aplastic) and **hypercellular** (ineffective erythropoiesis) causes of pancytopenia. **Why Dyskeratosis Congenita is the correct answer:** Dyskeratosis congenita is a rare inherited form of **Aplastic Anemia** caused by telomere biology disorders (e.g., mutations in the *DKC1* gene). Like idiopathic aplastic anemia, it is characterized by **pancytopenia with a hypocellular (empty) bone marrow**, where hematopoietic stem cells are replaced by fat [3]. It classically presents with the clinical triad of abnormal skin pigmentation, nail dystrophy, and oral leukoplakia. **Why the other options are incorrect:** * **Megaloblastic Anemia:** Characterized by ineffective hematopoiesis. The bone marrow is typically **hypercellular** with megaloblastic changes, but the cells fail to mature or exit into the peripheral blood, leading to pancytopenia [2]. * **Myelodysplastic Syndrome (MDS):** Often referred to as "pre-leukemia," MDS involves clonal stem cell disorders. The marrow is usually **hypercellular or normocellular** with prominent dysplastic features, but peripheral cytopenias occur due to high rates of intramedullary apoptosis [1]. * **Paroxysmal Nocturnal Hemoglobinuria (PNH):** While PNH can be associated with aplastic anemia, the classic "PNH-syndrome" often presents with a **cellular marrow** showing erythroid hyperplasia (due to hemolysis) despite peripheral pancytopenia. **High-Yield Clinical Pearls for NEET-PG:** * **Pancytopenia with Hypercellular Marrow:** Remember the mnemonic **"3Ms"**: **M**egaloblastic anemia, **M**DS, and **M**yelofibrosis (early stage) / **M**etastasis. * **Pancytopenia with Hypocellular Marrow:** Aplastic anemia, Hypoplastic MDS, and Fanconi Anemia [3]. * **Aleukemic Leukemia:** Another important cause of pancytopenia with a hypercellular marrow (packed with blasts) [3]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 613-614. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 594-595. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 662-663.

Question 385: The Coombs test is used for diagnosing which of the following conditions?

A. Thalassemia
B. Antibody-mediated hemolytic anemia (Correct Answer)
C. Sickle cell anemia
D. G6PD deficiency

Explanation: The **Coombs test (Antiglobulin Test)** is the gold standard for detecting immune-mediated hemolysis [1]. It identifies the presence of antibodies (IgG) or complement proteins (C3d) attached to red blood cells (Direct Coombs) or circulating in the serum (Indirect Coombs). **Why the correct answer is right:** Antibody-mediated hemolytic anemias, such as **Autoimmune Hemolytic Anemia (AIHA)**, Hemolytic Disease of the Newborn (HDN), and drug-induced hemolysis, involve the coating of RBCs by antibodies [1][2]. The Coombs reagent (antihuman globulin) causes agglutination of these sensitized RBCs, confirming an immune etiology for the anemia [1]. **Why the other options are incorrect:** * **Thalassemia:** This is a quantitative defect in globin chain synthesis (genetic). Diagnosis is made via **Hb Electrophoresis** or HPLC. * **Sickle Cell Anemia:** This is a qualitative structural defect in the beta-globin chain (HbS). Diagnosis involves the Sickling test, Solubility test, and **Hb Electrophoresis**. * **G6PD Deficiency:** This is an X-linked enzymopathy leading to oxidative stress. Diagnosis is confirmed by **G6PD enzyme assays** (performed after the hemolytic episode has subsided) and the presence of **Heinz bodies** or **Bite cells**. **High-Yield Clinical Pearls for NEET-PG:** * **Direct Coombs Test (DCT):** Detects antibodies already bound to the patient's RBCs *in vivo*. Used for AIHA and HDN (on baby's blood) [1]. * **Indirect Coombs Test (ICT):** Detects unbound antibodies in the patient's serum *in vitro*. Used for cross-matching and prenatal screening (on mother's blood). * **Warm AIHA:** Usually IgG mediated; associated with SLE or CLL [1]. * **Cold AIHA:** Usually IgM mediated; associated with *Mycoplasma* or Infectious Mononucleosis [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 651-652. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 603-604.

Question 386: Factor IX deficiency results in increased which of the following?

A. Prothrombin Time (PT)
B. Partial Thromboplastin Time (PTT) (Correct Answer)
C. Bleeding Time (BT)
D. Thrombin Time (TT)

Explanation: **Explanation:** Factor IX deficiency, also known as **Hemophilia B (Christmas Disease)**, is an X-linked recessive disorder that affects the **intrinsic pathway** of the coagulation cascade [1]. **Why PTT is the correct answer:** The **Activated Partial Thromboplastin Time (aPTT or PTT)** measures the integrity of the intrinsic (Factors XII, XI, IX, VIII) and common (Factors X, V, II, I) pathways [1]. Since Factor IX is a key component of the intrinsic pathway, its deficiency leads to a failure in the formation of the tenase complex, resulting in a **prolonged PTT**. **Why the other options are incorrect:** * **Prothrombin Time (PT):** PT measures the **extrinsic** (Factor VII) and common pathways [1]. Factor IX is not involved in the extrinsic pathway, so PT remains normal in Hemophilia B. * **Bleeding Time (BT):** BT is a measure of **platelet function** and primary hemostasis (platelet plug formation). In factor deficiencies, primary hemostasis is intact; therefore, BT is typically normal. * **Thrombin Time (TT):** TT measures the conversion of **fibrinogen to fibrin**. It is affected by heparin, hypofibrinogenemia, or dysfibrinogenemia, but not by deficiencies in the intrinsic pathway factors like Factor IX. **High-Yield Clinical Pearls for NEET-PG:** * **Mixing Study:** If PTT is prolonged, a mixing study is performed. If the PTT **corrects** with normal plasma, it indicates a factor deficiency (like Factor IX). * **Clinical Presentation:** Hemophilia B typically presents with deep tissue bleeding, **hemarthrosis** (bleeding into joints), and postsurgical bleeding. * **Inheritance:** Like Hemophilia A (Factor VIII deficiency), Hemophilia B is **X-linked recessive**, primarily affecting males. Factors II, VII, IX and X require vitamin K for posttranslational modification into their functional forms [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, pp. 128-130. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 582-583.

Question 387: Burkitt's lymphoma is positive for which CD marker?

A. CD5
B. CD15
C. CD20 (Correct Answer)
D. CD25

Explanation: **Explanation:** **Burkitt’s Lymphoma (BL)** is a highly aggressive B-cell non-Hodgkin lymphoma [1]. Since it originates from **germinal center B-cells**, it characteristically expresses pan-B-cell markers [1]. * **Why CD20 is correct:** CD20 is a definitive marker for mature B-cells [1]. Burkitt’s lymphoma cells consistently express surface immunoglobulins (IgM) and B-cell antigens, including **CD19, CD20, CD22, and CD10** [1]. It is also characteristically positive for **BCL-6**, while being negative for BCL-2 (an important distinction from Follicular Lymphoma). **Analysis of Incorrect Options:** * **CD5:** This is a T-cell marker also expressed by specific B-cell malignancies like **Chronic Lymphocytic Leukemia (CLL/SLL)** and **Mantle Cell Lymphoma** [1]. BL is CD5 negative. * **CD15:** Along with CD30, this is a classic marker for **Reed-Sternberg cells** in Hodgkin Lymphoma (specifically the Classical subtype). * **CD25:** This is the alpha chain of the IL-2 receptor, typically associated with **Hairy Cell Leukemia** and Adult T-cell Leukemia/Lymphoma (ATLL). **High-Yield Clinical Pearls for NEET-PG:** * **Cytogenetics:** Characterized by **t(8;14)** translocation involving the ***MYC*** gene and the IgH promoter. * **Morphology:** Shows a classic **"Starry-sky appearance"** on histology (tingible body macrophages acting as "stars" against a "sky" of dark neoplastic B-cells). * **Proliferation:** It has a near **100% Ki-67 growth fraction**, indicating extremely rapid cell turnover. * **Variants:** Endemic (African/Jaw involvement), Sporadic (Abdominal/Ileocecal), and Immunodeficiency-associated [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, p. 598. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, pp. 605-606.

Question 388: Blast crises in Chronic Myeloid Leukemia (CML) are characterized by which of the following?

A. Blast cells in blood or bone marrow > 10%
B. Blast cells in blood >= 20% (Correct Answer)
C. Blast cells absent
D. All of the above

Explanation: Chronic Myeloid Leukemia (CML) is a myeloproliferative neoplasm characterized by the Philadelphia chromosome $t(9;22)$. It typically progresses through three distinct phases: the Chronic Phase, the Accelerated Phase, and the **Blast Crisis (Blast Phase)**. **1. Why Option B is Correct:** According to the WHO classification, the **Blast Crisis** is defined by the presence of **$\ge$ 20% blasts** in the peripheral blood or bone marrow [1]. This stage represents the transformation of CML into an acute leukemia [1]. Interestingly, in 70% of cases, the blasts are myeloid (AML-like), while in 30%, they are lymphoid (ALL-like), reflecting the origin of CML in a pluripotent stem cell. **2. Why Other Options are Incorrect:** * **Option A:** A blast count of **10-19%** (along with other criteria like persistent thrombocytopenia or increasing splenomegaly) defines the **Accelerated Phase**, not the Blast Crisis. * **Option C:** Blasts are never absent in CML; even in the Chronic Phase, blasts are typically present but remain $<10\%$. **High-Yield Clinical Pearls for NEET-PG:** * **Defining Genetic Abnormality:** $t(9;22)$ resulting in the *BCR-ABL1* fusion gene, which encodes a constitutively active tyrosine kinase. * **Leukocyte Alkaline Phosphatase (LAP) Score:** Characteristically **decreased** in CML (helps differentiate it from a Leukemoid Reaction where LAP is elevated). * **Basophilia:** An increase in peripheral blood basophils is a hallmark of CML and often heralds progression to the accelerated phase. * **Treatment:** Imatinib (Tyrosine Kinase Inhibitor) is the first-line therapy. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 613-614.

Question 389: Comment on the type of anemia observed in a peripheral smear.

A. Pernicious anemia (Correct Answer)
B. Iron deficiency anemia
C. Sickle cell anemia
D. Hereditary spherocytosis

Explanation: ***Pernicious anemia*** - Characterized by **macro-ovalocytes** (large, oval-shaped RBCs) and **hypersegmented neutrophils** (>5 nuclear lobes) on peripheral smear. - Results from **vitamin B12 deficiency** due to lack of **intrinsic factor**, leading to megaloblastic anemia with distinctive morphological changes. *Iron deficiency anemia* - Shows **microcytic hypochromic** RBCs with **pencil cells** and **target cells** on peripheral smear. - Associated with **decreased serum ferritin** and **increased TIBC**, not the megaloblastic changes seen in this case. *Sickle cell anemia* - Peripheral smear reveals characteristic **sickle-shaped cells** (drepanocytes) and **target cells**. - Caused by **hemoglobin S mutation**, leading to sickling under hypoxic conditions, not megaloblastic morphology. *Hereditary spherocytosis* - Shows **spherocytes** (round RBCs lacking central pallor) and **increased osmotic fragility** on peripheral smear. - Results from **membrane protein defects** causing loss of membrane surface area, distinct from megaloblastic changes.

Question 390: Defect leading to thalassemia lies in which component?

A. Hemoglobin (Correct Answer)
B. Osmotic fragility
C. RBC membrane
D. Platelets

Explanation: ### Explanation **Correct Option: A. Hemoglobin** Thalassemia is a group of hereditary microcytic hemolytic anemias characterized by a **quantitative defect** in hemoglobin synthesis [1]. The primary pathology lies in the reduced or absent production of one or more of the globin chains ($\alpha$ or $\beta$) [1], [3]. This leads to an imbalance between the globin chains, causing the precipitation of the excess chains (e.g., $\alpha$-tetramers in $\beta$-thalassemia), which damages the RBC membrane and leads to ineffective erythropoiesis and hemolysis [4]. **Analysis of Incorrect Options:** * **B. Osmotic Fragility:** This is a laboratory test, not a structural component. In Thalassemia, osmotic fragility is actually **decreased** (cells are more resistant to lysis) because the target cells have a high surface-area-to-volume ratio. * **C. RBC Membrane:** Defects in the RBC membrane proteins (like spectrin or ankyrin) lead to conditions like **Hereditary Spherocytosis** or Elliptocytosis, not Thalassemia. * **D. Platelets:** Thalassemia is a disorder of erythropoiesis; platelets are typically not the primary site of the genetic defect, though secondary splenomegaly in Thalassemia major may lead to sequestration. **NEET-PG High-Yield Pearls:** * **Quantitative vs. Qualitative:** Thalassemia is a *quantitative* defect (less globin produced), whereas Sickle Cell Anemia is a *qualitative* defect (abnormal globin structure) [1]. * **Peripheral Smear:** Characterized by **Target cells** (leptocytes), microcytic hypochromic RBCs, and basophilic stippling [2]. * **Mentzer Index:** (MCV/RBC count) $< 13$ suggests Thalassemia trait, while $> 13$ suggests Iron Deficiency Anemia. * **Gold Standard Diagnosis:** Hemoglobin Electrophoresis or HPLC (High-Performance Liquid Chromatography). **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 587-588. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 590-591. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, p. 650. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 647-648.

Practice by Chapter

Anemias: Classification and Approach

Practice Questions

Hemolytic Anemias

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Myeloproliferative Neoplasms

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Myelodysplastic Syndromes

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Acute Leukemias

Practice Questions

Chronic Leukemias

Practice Questions

Lymphomas and Lymphoid Neoplasms

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Plasma Cell Disorders

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Bleeding Disorders

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Thrombotic Disorders

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