Hematopathology — MCQs

Hematopathology Indian Medical PG Practice Questions and MCQs

Question 861: Which of the following is NOT a cause for Disseminated Intravascular Coagulation (DIC)?

A. Septicemia
B. Visceral carcinoma
C. Cholera (Correct Answer)
D. Antepartum hemorrhage

Explanation: **Explanation:** Disseminated Intravascular Coagulation (DIC) is a thrombohemorrhagic disorder characterized by the systemic activation of the coagulation cascade, leading to widespread fibrin deposition in the microvasculature and subsequent consumption of clotting factors and platelets. **Why Cholera is the Correct Answer:** **Cholera** is an acute diarrheal disease caused by *Vibrio cholerae*. Its primary pathology is massive intestinal secretion of water and electrolytes leading to severe dehydration and hypovolemic shock. Unlike septicemia caused by Gram-negative bacteria [1], Cholera is a non-invasive infection; the toxin does not typically trigger the systemic inflammatory response syndrome (SIRS) or the release of tissue factor required to initiate DIC. **Analysis of Incorrect Options:** * **Septicemia:** This is the most common cause of DIC. Endotoxins (Gram-negative) or exotoxins (Gram-positive) trigger cytokine release (TNF, IL-1), which induces endothelial cells to express tissue factor and inhibits natural anticoagulants [1], [2]. * **Visceral Carcinoma:** Mucin-secreting adenocarcinomas (e.g., pancreas, prostate) release procoagulant substances into the circulation, leading to chronic DIC (Trousseau syndrome) [2]. * **Antepartum Hemorrhage (APH):** Obstetric complications like Abruptio Placentae or retained dead fetus allow placental tissue factor to enter maternal circulation, causing fulminant DIC [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Pathogenesis:** The "final common pathway" is the systemic entry of **Tissue Factor** into the blood [2]. * **Peripheral Smear:** Characterized by **Schistocytes** (fragmented RBCs) due to microangiopathic hemolytic anemia (MAHA) [4]. * **Lab Profile:** Prolonged PT/aPTT, decreased Fibrinogen, and **elevated D-dimer** (most sensitive marker) [4]. * **Waterhouse-Friderichsen Syndrome:** Massive bilateral adrenal hemorrhage occurring as a complication of DIC in Meningococcemia [3]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 63-64. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 671-673. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 672-673. [4] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 625-626.

Question 862: Increased rouleaux formation in the peripheral blood is a characteristic feature of which of the following conditions?

A. Multiple myeloma (Correct Answer)
B. Non-Hodgkin's lymphoma
C. Tuberculosis
D. Malaria

Explanation: **Explanation:** **Rouleaux formation** refers to the stacking of red blood cells (RBCs) like a "pile of coins." This occurs when the negative surface charge of RBCs (zeta potential), which normally keeps them apart, is neutralized by an increase in plasma proteins. **Why Multiple Myeloma is correct:** Multiple Myeloma is a plasma cell dyscrasia characterized by the overproduction of monoclonal immunoglobulins (**M-proteins**). These large, positively charged proteins (globulins) neutralize the negative charge on the RBC surface, allowing them to adhere to one another and form stacks [1]. This is a hallmark peripheral smear finding in myeloma patients and is also responsible for the characteristically high **Erythrocyte Sedimentation Rate (ESR)** seen in this condition. **Why other options are incorrect:** * **Non-Hodgkin’s Lymphoma:** While some lymphomas can occasionally cause hypergammaglobulinemia, it is not a classic or defining feature like it is in Multiple Myeloma. * **Tuberculosis:** Chronic infections can increase fibrinogen and globulins (acute phase reactants), leading to a high ESR, but the degree of protein elevation is rarely sufficient to produce the prominent rouleaux seen in plasma cell disorders. * **Malaria:** Peripheral smears in malaria typically show intracellular parasites (ring forms, gametocytes) or hemolysis, not rouleaux formation. **High-Yield Clinical Pearls for NEET-PG:** * **Zeta Potential:** The negative charge on RBCs maintained by sialic acid. Its neutralization leads to Rouleaux. * **Differential Diagnosis:** Rouleaux is also seen in Waldenström Macroglobulinemia (due to IgM) and severe inflammatory states (due to high fibrinogen) [1], [2]. * **Cold Agglutinins vs. Rouleaux:** Do not confuse Rouleaux with **Auto-agglutination** (seen in Cold AIHA). Agglutination forms irregular "clumps" rather than linear "stacks" and does not disperse with saline. **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, pp. 607-608. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 616-617.

Question 863: What is the best method for hemoglobin estimation?

A. Sahli's hemoglobinometer
B. Cyanmethemoglobin method (Correct Answer)
C. Calorimetric method
D. None of the above

Explanation: **Explanation:** The **Cyanmethemoglobin (HiCN) method** is the gold standard and the internationally recommended method (by the ICSH) for hemoglobin estimation. **Why it is the best method:** 1. **Universal Conversion:** It converts almost all forms of hemoglobin (oxyhemoglobin, deoxyhemoglobin, carboxyhemoglobin, and methemoglobin) into a single stable compound called cyanmethemoglobin. The only exception is **sulfhemoglobin**. 2. **Stability:** The color produced is highly stable and does not fade quickly, allowing for accurate spectrophotometric measurement. 3. **Standardization:** Commercially available Drabkin’s solution and certified HiCN standards ensure high precision and minimal inter-observer variability. **Analysis of Incorrect Options:** * **Sahli’s Method (Acid Hematin):** This is an obsolete visual method. It is prone to significant errors (up to 10-15%) due to subjective color matching, slow conversion of hemoglobin to acid hematin, and the fact that it does not measure carboxy- or methemoglobin. * **Calorimetric Method:** While the HiCN method is technically a colorimetric/spectrophotometric technique, "Calorimetric" is a broad category, not a specific method. In the context of this question, the specific chemical reaction (Cyanmethemoglobin) is the superior answer. **High-Yield Clinical Pearls for NEET-PG:** * **Drabkin’s Solution:** Contains Potassium Ferricyanide (converts Hb to MetHb) and Potassium Cyanide (converts MetHb to HiCN). * **Wavelength:** Absorbance is measured at **540 nm**. * **Lipemia/Leukocytosis:** High WBC counts (>20,000/µL) or high lipids can cause turbidity in the solution, leading to a falsely elevated Hb reading. * **Sulfhemoglobin:** This is the only form of hemoglobin **not** measured by the HiCN method.

Question 864: Which of the following is true about alpha-thalassemia trait?

A. Increased HbF
B. Increased HbA2
C. Microcytosis (Correct Answer)
D. Severe anemia

Explanation: **Explanation:** **Alpha-thalassemia trait** (also known as alpha-thalassemia minor) occurs when there is a deletion of two of the four alpha-globin genes (--/αα or -α/-α). 1. **Why Microcytosis is Correct:** In alpha-thalassemia, the reduced synthesis of alpha-globin chains leads to a relative excess of beta-globin chains. This imbalance results in deficient hemoglobinization of red blood cells. Consequently, the RBCs produced are small (**microcytic**) [3] and pale (**hypochromic**). On a complete blood count (CBC), this is reflected as a low Mean Corpuscular Volume (MCV) and low Mean Corpuscular Hemoglobin (MCH), even though the anemia is typically mild or absent [1]. 2. **Why Other Options are Incorrect:** * **Increased HbF & HbA2:** These are classic markers for **Beta-thalassemia trait**. In alpha-thalassemia, all adult hemoglobins (HbA, HbA2, and HbF) require alpha-chains. Therefore, the ratio between them remains normal. HbA2 and HbF levels are typically **normal or low** in alpha-thalassemia trait [1]. * **Severe Anemia:** Alpha-thalassemia trait is usually **asymptomatic** or presents with very mild anemia [1]. Severe anemia in the alpha-thalassemia spectrum is seen in **HbH disease** (3-gene deletion) or **Hydrops Fetalis** (4-gene deletion). **High-Yield Clinical Pearls for NEET-PG:** * **Mentzer Index:** (MCV/RBC count) is usually **<13** in thalassemia, helping differentiate it from Iron Deficiency Anemia (>13). * **Diagnosis:** Unlike Beta-thalassemia, alpha-thalassemia trait **cannot** be diagnosed by Hb electrophoresis (as HbA2 is normal) [2]. It requires genetic testing (PCR) for definitive diagnosis [2]. * **Hb Barts:** A tetramer of gamma chains ($\gamma_4$), seen in neonates with alpha-thalassemia. * **HbH:** A tetramer of beta chains ($\beta_4$), seen in 3-gene deletion; shows "golf ball" inclusions with supra-vital stains [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. 649-650. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 600-601. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 590-591.

Question 865: A 35-year-old woman is evaluated for a long history of easy bruising. The peripheral smear shows only a few, large, young platelets, while other cell lines are normal. Marrow studies show increased megakaryocytes. Which of the following is the most likely diagnosis?

A. Idiopathic thrombocytopenic purpura (Correct Answer)
B. Microangiopathic hemolytic anemia
C. Thrombasthenia
D. Thrombotic thrombocytopenic purpura

Explanation: **Explanation:** The clinical presentation of easy bruising, isolated thrombocytopenia (implied by "few platelets"), and increased bone marrow megakaryocytes points toward **Immune Thrombocytopenic Purpura (ITP)** [1]. **1. Why Option A is Correct:** ITP is an autoimmune disorder where IgG antibodies are directed against platelet glycoproteins (like GpIIb/IIIa). This leads to peripheral destruction of platelets by splenic macrophages. The bone marrow responds to this peripheral loss by increasing the number of **megakaryocytes** (compensatory hyperplasia) [2]. The presence of **large, young platelets** (megathrombocytes) on the peripheral smear indicates accelerated thrombopoiesis, a hallmark of peripheral destruction rather than marrow failure [1]. **2. Why Incorrect Options are Wrong:** * **Microangiopathic Hemolytic Anemia (MAHA):** While it involves thrombocytopenia, the peripheral smear would characteristically show **schistocytes** (fragmented RBCs) and signs of hemolysis, which are absent here. * **Thrombasthenia (Glanzmann’s):** This is a qualitative platelet disorder (defect in GpIIb/IIIa). Platelet **count and morphology are typically normal**, but platelet aggregation is impaired. * **Thrombotic Thrombocytopenic Purpura (TTP):** TTP presents with a classic pentad: microangiopathic hemolytic anemia, thrombocytopenia, neurological symptoms, fever, and renal failure [3]. The absence of schistocytes and systemic symptoms rules this out. **NEET-PG High-Yield Pearls:** * **ITP Diagnosis:** It is a diagnosis of exclusion. Look for isolated thrombocytopenia with normal RBC and WBC counts [1]. * **Bone Marrow:** Essential to rule out leukemia in elderly patients, but in ITP, it characteristically shows **increased or normal megakaryocytes** [2]. * **Treatment:** First-line therapy is usually **Corticosteroids** or IVIG [1]. Splenectomy is considered for refractory cases. * **Key Association:** In adults, ITP can be associated with HIV, HCV, or SLE. Always check for secondary causes. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 666-667. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 620-621. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 667-668.

Question 866: All of the following are true about the etiology of primary myelofibrosis, EXCEPT:

A. JAK2 mutation is seen in 50% of cases.
B. Overproduction of transforming growth factor.
C. Overproduction of osteoprotegerin.
D. Mutations in the thrombopoietin receptor Mpl occur in 50% of cases. (Correct Answer)

Explanation: **Explanation:** Primary Myelofibrosis (PMF) is a chronic myeloproliferative neoplasm (MPN) characterized by bone marrow fibrosis, extramedullary hematopoiesis, and splenomegaly. The fibrosis is a reactive process driven by the neoplastic clone [3]. **Why Option D is the Correct Answer (The False Statement):** While mutations in the **MPL (thrombopoietin receptor)** gene are a hallmark of PMF, they are relatively rare, occurring in only **5–10%** of cases [1]. The statement claiming a 50% frequency is incorrect, making it the right choice for an "EXCEPT" question. **Analysis of Other Options:** * **Option A (JAK2 Mutation):** This is a true statement. The **JAK2 V617F** mutation is the most common genetic driver in PMF, found in approximately **50–60%** of patients [1]. * **Option B (TGF-β):** This is true. Neoplastic megakaryocytes release fibrogenic cytokines, most notably **Transforming Growth Factor-beta (TGF-β)** [3]. TGF-β stimulates non-neoplastic fibroblasts to deposit excessive collagen, leading to marrow fibrosis. * **Option C (Osteoprotegerin):** This is true. Megakaryocytes also secrete **Osteoprotegerin**, which inhibits osteoclasts. This shift in balance leads to the **osteosclerosis** (increased bone density) often seen in advanced PMF. **NEET-PG High-Yield Pearls:** 1. **Genetic Triad:** The three "driver mutations" in PMF are **JAK2** (50-60%), **CALR** (Calreticulin, 25-30%), and **MPL** (5-10%) [1], [2]. Cases lacking all three are termed "Triple Negative." 2. **Peripheral Smear:** Characterized by a **leukoerythroblastic picture** (immature WBCs and RBCs) and hallmark **Dacrocytes** (teardrop-shaped RBCs). 3. **Dry Tap:** Bone marrow aspiration often results in a "dry tap" due to extensive fibrosis; a trephine biopsy is essential for diagnosis. **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. 624. [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. 627-628. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 614-615.

Question 867: Increased LDH is an important marker for:

A. Bulky disease (Correct Answer)
B. Lymphoma
C. Liver metastasis
D. Lung metastasis

Explanation: **Explanation:** **Lactate Dehydrogenase (LDH)** is a cytoplasmic enzyme present in almost all body tissues. It is released into the bloodstream during cell injury or rapid cell turnover. **Why "Bulky Disease" is the correct answer:** In the context of oncology and hematopathology, LDH serves as a surrogate marker for **tumor burden** and **proliferative rate**. "Bulky disease" refers to a large tumor mass (typically >7–10 cm in lymphomas). Because bulky tumors have a high number of cells undergoing rapid turnover, necrosis, and anaerobic metabolism, they release significant amounts of LDH [1]. In clinical practice, LDH levels are used to estimate the total volume of the tumor, predict prognosis, and monitor response to therapy [3]. **Analysis of Incorrect Options:** * **B. Lymphoma:** While LDH is elevated in many lymphomas (especially high-grade ones like DLBCL or Burkitt’s), it is not a diagnostic marker for the disease itself [2]. It is used to stage the lymphoma and determine if the disease is "bulky." * **C & D. Liver and Lung Metastasis:** While LDH can be elevated in metastatic disease, it is non-specific. Other markers (like ALT/AST for liver or imaging for lung) are more clinically relevant. LDH specifically correlates better with the *volume* (bulk) of the metastasis rather than the *site*. **High-Yield Pearls for NEET-PG:** * **Prognostic Significance:** LDH is a key component of the **International Prognostic Index (IPI)** for Non-Hodgkin Lymphoma. * **Tumor Lysis Syndrome (TLS):** High baseline LDH is a major risk factor for developing TLS upon starting chemotherapy. * **Other High LDH States:** Dysgerminoma (marker), Megaloblastic anemia (very high levels due to ineffective erythropoiesis), and PJP pneumonia (in HIV patients). **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 235-236. [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, p. 606. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 254-255.

Question 868: Within how many hours of initiation should a blood transfusion be completed?

A. 1-4 hours (Correct Answer)
B. 3-6 hours
C. 4-8 hours
D. 8-12 hours

Explanation: **Explanation:** The standard protocol for blood transfusion dictates that a unit of blood (typically Packed Red Blood Cells) must be completed within **1 to 4 hours** of initiation. **Why 1-4 hours is correct:** * **The 30-minute rule:** Transfusion should ideally start within 30 minutes of the unit leaving the blood bank refrigerator (stored at 2–6°C). * **The 4-hour limit:** Once the blood bag is spiked and exposed to room temperature, the risk of **bacterial proliferation** (especially Gram-negative organisms like *Yersinia enterocolitica*) increases significantly. Furthermore, red cell hemolysis and loss of function occur as the blood warms. Completing the transfusion within 4 hours minimizes the risk of septic transfusion reactions. **Why other options are incorrect:** * **B, C, and D:** Any duration exceeding 4 hours is clinically unsafe. Prolonged exposure to ambient temperature promotes the growth of contaminants and increases the risk of transfusion-transmitted infections (TTI). If a patient cannot tolerate the volume within 4 hours (e.g., congestive heart failure), the unit should be split into smaller aliquots by the blood bank. **High-Yield Clinical Pearls for NEET-PG:** * **Rate of Transfusion:** In a stable patient, the first 15 minutes should be slow (approx. 2 ml/min) to monitor for acute hemolytic reactions. * **Platelets and FFP:** These should be transfused more rapidly, usually within 30–60 minutes. * **Commonest Contaminant:** *Staphylococcus epidermidis* (Gram-positive) is the most common in platelets, while *Yersinia enterocolitica* (Gram-negative) is classically associated with refrigerated RBCs. * **Change of Sets:** The blood administration set (with a 170–200 micron filter) must be changed after every 2 units or every 4 hours to prevent clogging and bacterial growth.

Question 869: Which anticoagulant is the preferred choice for performing coagulation studies?

A. EDTA
B. Heparin
C. Tri-sodium citrate (Correct Answer)
D. Double oxalate

Explanation: **Tri-sodium citrate (3.2%)** is the anticoagulant of choice for coagulation studies (PT, APTT, and Fibrinogen) because it is a **reversible calcium chelator**. It binds to ionized calcium, effectively halting the coagulation cascade [1]. Its primary advantage is that the process can be reversed by adding calcium back to the plasma during testing [1]. Furthermore, it preserves labile coagulation factors (Factor V and Factor VIII) better than other anticoagulants. For routine coagulation tests, a strict **9:1 ratio** of blood to citrate is required to ensure accurate results. **Why other options are incorrect:** * **EDTA (Ethylene Diamine Tetra-acetic Acid):** The gold standard for routine hematology (CBC/ESR) because it preserves cell morphology. However, it is unsuitable for coagulation studies as it irreversibly inhibits the coagulation cascade and can lead to the degradation of Factors V and VIII. * **Heparin:** It acts by activating Antithrombin III, which inhibits Thrombin and Factor Xa [2]. Since it directly interferes with the very enzymes being measured in coagulation assays, it would cause falsely prolonged results. It is, however, the preferred anticoagulant for arterial blood gas (ABG) analysis and osmotic fragility tests. * **Double Oxalate (Wintrobe’s mixture):** A mixture of ammonium and potassium oxalate. It is rarely used today as it causes cell shrinkage and interferes with many biochemical and coagulation assays. **High-Yield Clinical Pearls for NEET-PG:** * **Concentration:** 3.2% (0.109 mol/L) citrate is preferred over 3.8% because the latter can over-anticoagulate the sample, leading to falsely prolonged PT/APTT. * **Polycythemia Correction:** If a patient’s hematocrit is >55%, the volume of citrate must be adjusted (reduced) because there is less plasma relative to the anticoagulant. * **Black Top Tube:** Contains 3.8% citrate (4:1 ratio) specifically for ESR measurement via the Westergren method. * **Blue Top Tube:** Contains 3.2% citrate (9:1 ratio) for coagulation profiles. **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. 582-584.

Question 870: Which mutation is not seen in hereditary spherocytosis?

A. Ankyrin
B. Spectrin
C. Band-3
D. Na+ Cl- channel protein (Correct Answer)

Explanation: **Explanation:** Hereditary Spherocytosis (HS) is a common inherited hemolytic anemia characterized by a defect in the red blood cell (RBC) membrane proteins [1]. The fundamental pathology involves a **deficiency or abnormality in proteins that link the cytoskeleton to the lipid bilayer**, leading to the loss of membrane surface area and the formation of spherical, fragile erythrocytes [1], [2]. **Why Option D is Correct:** **Na+ Cl- channel proteins** are not involved in the structural integrity of the RBC membrane cytoskeleton. While RBCs do have ion transporters (like the Na+/K+ ATPase), mutations in these specific channels are not a cause of HS. Instead, the "leakiness" to sodium seen in HS cells is a secondary physiological consequence of the membrane defect, not the primary genetic mutation. **Why Other Options are Incorrect:** * **Ankyrin (Option A):** This is the **most common** mutation in HS (approx. 50-60% of cases). It anchors spectrin to the transmembrane protein Band-3 [1]. * **Spectrin (Option B):** Mutations in α-spectrin or β-spectrin lead to a weakened skeletal framework, causing the membrane to "pinch off" as microvesicles [1]. * **Band-3 (Option C):** This is a major transmembrane protein. Mutations here are the second most common cause of HS and often present with a milder phenotype [1]. **NEET-PG High-Yield Pearls:** * **Inheritance:** Most commonly Autosomal Dominant (75%). * **Gold Standard Test:** Eosin-5-maleimide (EMA) binding test (Flow cytometry). * **Confirmatory Test:** Osmotic Fragility Test (increased fragility) [2]. * **Peripheral Smear:** Spherocytes (small, dark RBCs lacking central pallor) and increased MCHC (>36 g/dL) [2]. * **Complications:** Pigmented gallstones (calcium bilirubinate) and Aplastic Crisis (associated with Parvovirus B19) [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. 640-641. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 597-598.

Practice by Chapter

Anemias: Classification and Approach

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Hemolytic Anemias

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Myeloproliferative Neoplasms

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Myelodysplastic Syndromes

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Acute Leukemias

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Chronic Leukemias

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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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