Hematology Practice Questions

Q: A patient with a blood pressure of 90/60 mm Hg presents with pronounced cyanosis. Blood drawn from peripheral veins is observed to be chocolate brown in colour. What is the most likely diagnosis?

Methemoglobinemia. The clinical presentation of **pronounced cyanosis** unresponsive to oxygen, combined with **chocolate-brown colored blood**, is a classic hallmark of **Methemoglobinemia**. **1. Why Methemoglobinemia is correct:** Methemoglobinemia occurs when the iron in hemoglobin is oxidized from the **ferrous (Fe²⁺)** state to the **ferric (Fe³⁺)** state. Ferric iron cannot bind oxygen. Furthermore, the presence of ferric iron causes a "left shift" in the oxygen-dissociation curve, meaning the remaining ferrous heme groups bind oxygen too tightly, preventing its release to tissues [2]. The characteristic chocolate-brown color of the blood is due to the dark pigment of methemoglobin, which does not change color even when exposed to 100% oxygen [1]. **2. Why the other options are incorrect:** * **Hypovolemic, Cardiogenic, and Hemorrhagic Shock:** While these conditions can cause hypotension (90/60 mm Hg) and peripheral cyanosis due to poor tissue perfusion (stagnant hypoxia), they **do not** change the color of the blood to chocolate brown. In these types of shock, the blood remains dark red (deoxygenated) but turns bright red upon exposure to oxygen or during arterial sampling. **3. Clinical Pearls for NEET-PG:** * **The "Saturation Gap":** A key diagnostic clue is a significant difference (>5%) between the oxygen saturation measured by pulse oximetry (which is falsely low, often hovering around 85%) and the arterial oxygen saturation (SaO₂) calculated on an ABG. * **Common Triggers:** Exposure to oxidizing agents like **Nitrites, Benzocaine, Dapsone, or Primaquine** [1], [2]. * **Antidote:** The treatment of choice is **Methylene Blue** (acts as an electron donor to reduce Fe³⁺ back to Fe²⁺). * **Note:** Methylene blue is ineffective in patients with **G6PD deficiency**; in such cases, Vitamin C or exchange transfusion is used.

Q: A 32-year-old male presents with abdominal pain and vomiting. He also complains of psychiatric symptoms and visual hallucinations. What is the most likely diagnosis?

Intermittent Porphyria. ### Explanation The correct diagnosis is **Acute Intermittent Porphyria (AIP)**. This condition is an autosomal dominant metabolic disorder caused by a deficiency in the enzyme **Porphobilinogen deaminase (PBG-D)**, leading to the accumulation of porphyrin precursors like ALA and PBG. **Why it is correct:** AIP is classically characterized by the **"Triad of Ps"**: 1. **P**ain in abdomen (most common symptom, often severe and colicky). 2. **P**sychological symptoms (anxiety, agitation, hallucinations, or psychosis). 3. **P**olyneuropathy (motor weakness). The patient’s presentation of abdominal pain, vomiting, and visual hallucinations fits the classic "neurovisceral" attack of AIP. Notably, unlike other porphyrias, AIP **does not** present with cutaneous photosensitivity. **Why other options are incorrect:** * **Hypo/Hyperthyroidism:** While thyroid disorders can cause psychiatric symptoms (depression in hypo; anxiety/psychosis in hyper), they do not typically present with acute, severe abdominal pain and vomiting as the primary clinical feature. * **Hysteria:** This is a diagnosis of exclusion. Given the systemic nature of the symptoms (vomiting and abdominal pain), an organic cause like porphyria must be ruled out first. AIP is often misdiagnosed as a psychiatric disorder or a surgical emergency. **NEET-PG High-Yield Pearls:** * **Enzyme Defect:** Porphobilinogen deaminase (also known as Hydroxymethylbilane synthase). * **Urine Finding:** Urine turns **"Port-wine red"** on standing due to the oxidation of porphobilinogen to porphobilin. * **Precipitating Factors:** Barbiturates, sulfonamides, alcohol, and fasting (the "5 Ps": **P**ills, **P**upping/Pregnancy, **P**aint/Alcohol, **P**hage/Starvation, **P**eriods). * **Treatment:** Intravenous **Hemin** (suppresses ALA synthase) and high-dose glucose.

Q: A patient presents with ecchymosis and petechiae all over the body, with no hepato-splenomegaly. All of the following are true regarding this condition EXCEPT:

Bleeding into the joints. The clinical presentation of petechiae and ecchymosis without hepatosplenomegaly strongly suggests **Immune Thrombocytopenic Purpura (ITP)**. In ITP, there is isolated thrombocytopenia due to autoantibody-mediated destruction of platelets [1]. ### **Explanation of Options** * **Option B (Correct Answer):** Bleeding into the joints (**Hemarthrosis**) is a hallmark of **coagulation factor deficiencies** (e.g., Hemophilia), not platelet disorders [1]. Platelet disorders (like ITP) typically present with superficial "mucocutaneous" bleeding, such as petechiae, purpura, epistaxis, and gum bleeding [1]. * **Option A:** In ITP, the bone marrow responds to peripheral platelet destruction by increasing production. Therefore, an **increased number of megakaryocytes** (platelet precursors) is a classic compensatory finding. * **Option C:** The primary pathology is the immune-mediated destruction of platelets in the spleen, leading to **decreased platelets** (thrombocytopenia) in the peripheral blood [1]. * **Option D:** This describes **Acute ITP**, which is most common in children following a viral infection. It is typically self-limiting, with approximately **80% of cases resolving spontaneously** within weeks to months. ### **NEET-PG High-Yield Pearls** * **ITP Diagnosis:** It is a diagnosis of exclusion. The presence of splenomegaly should prompt a search for other causes (e.g., Leukemia, Cirrhosis) [2]. * **First-line Treatment:** Corticosteroids (Prednisolone) or IVIG. * **Platelet Transfusion:** Generally contraindicated in ITP unless there is life-threatening hemorrhage, as the autoantibodies will destroy the transfused platelets rapidly. * **Chronic ITP:** Defined as thrombocytopenia persisting for >12 months; more common in adults [1].

Q: A 25-year-old female presents with complaints of fever and weakness. On examination, there is splenomegaly of 3 cm below the costal margin. Her Hb is 8 gm/dL, TLC is 3,000/mm3, and platelet count is 80,000 mm3. Which of the following is the least likely diagnosis?

Aplastic anemia. ### Explanation The patient presents with **pancytopenia** (anemia, leucopenia, and thrombocytopenia) and **splenomegaly**. The key to solving this question lies in the clinical finding of an enlarged spleen [1]. **1. Why Aplastic Anemia is the Correct Answer (Least Likely):** Aplastic anemia is characterized by bone marrow failure leading to pancytopenia. A fundamental clinical rule in hematology is that **Aplastic Anemia does not cause splenomegaly.** If a patient with pancytopenia has an enlarged spleen, the clinician must look for alternative diagnoses like leukemia, myelofibrosis, or hypersplenism [2]. The presence of splenomegaly in a suspected case of aplastic anemia should prompt a search for an "infiltrative" cause rather than primary marrow failure. **2. Analysis of Other Options:** * **Acute Lymphocytic Leukemia (ALL):** This is a common cause of pancytopenia due to marrow infiltration by blasts. Splenomegaly is a frequent finding in ALL due to extramedullary involvement. * **Anemia of Chronic Disease (ACD):** While typically presenting as isolated anemia, chronic inflammatory states or infections (like Tuberculosis or Kala-azar) can cause both cytopenias and reactive splenomegaly. * **Megaloblastic Anemia:** Severe Vitamin B12 or Folate deficiency leads to ineffective erythropoiesis, often resulting in pancytopenia. Mild to moderate splenomegaly is seen in about 10–15% of these cases. **3. Clinical Pearls for NEET-PG:** * **Pancytopenia + Splenomegaly:** Think of Malaria, Kala-azar, Leukemia, Lymphoma, Cirrhosis (Portal Hypertension), or Gaucher’s disease. * **Pancytopenia - Splenomegaly:** Think of Aplastic Anemia, PNH (Paroxysmal Nocturnal Hemoglobinuria), or early-stage Myelodysplastic Syndrome (MDS). * **Gold Standard:** The definitive investigation to differentiate these conditions is a **Bone Marrow Aspiration and Biopsy**. In Aplastic Anemia, the marrow will be "hypocellular" with increased fat spaces.

Q: What is the basic defect in Hemoglobin S?

Altered solubility. ### Explanation The fundamental defect in **Hemoglobin S (HbS)** is a qualitative change in the beta-globin chain, where **glutamic acid** (polar/hydrophilic) is replaced by **valine** (non-polar/hydrophobic) at the **6th position** [1]. **1. Why "Altered Solubility" is Correct:** The substitution of a hydrophobic amino acid (valine) creates a "sticky patch" on the surface of the hemoglobin molecule. In the **deoxygenated state**, these patches interact, causing HbS molecules to polymerize into long, rigid insoluble fibers [2]. This **polymerization** (decreased solubility) distorts the red blood cell into a sickle shape, leading to vaso-occlusion and hemolysis. **2. Analysis of Incorrect Options:** * **Altered Function:** While the clinical outcome is dysfunctional, the "basic defect" refers to the physical property change (solubility) that precedes the functional failure. * **Altered Stability:** This refers to **unstable hemoglobins** (e.g., Hb Koln) that precipitate as Heinz bodies. HbS is stable until it deoxygenates. * **Altered Oxygen Binding Capacity:** This is characteristic of **Hemoglobin M** (methemoglobinemia) or high-affinity variants (e.g., Hb Chesapeake) [3]. HbS actually has a *decreased* oxygen affinity (right shift of the dissociation curve), but this is a secondary effect, not the primary defect. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Autosomal Recessive; Point mutation (Missense) in the HBB gene on Chromosome 11. * **Sickling Triggers:** Hypoxia, acidosis, dehydration, and cold. * **Protective Factor:** HbF (Fetal Hemoglobin) inhibits polymerization; hence, Hydroxyurea (which increases HbF) is the treatment of choice. * **Metabolic Benefit:** Heterozygotes (Sickle cell trait) have a survival advantage against *Plasmodium falciparum* malaria.

Q: What is the most common site of histiocytosis?

Bone. Langerhans Cell Histiocytosis (LCH) is a rare proliferative disorder of dendritic (Langerhans) cells. For NEET-PG, it is crucial to recognize that LCH can present as a single-system or multi-system disease. **1. Why Bone is the Correct Answer:** The **bone** is the most frequently involved organ in LCH, affected in approximately **80% of cases**. The most common site within the skeletal system is the **skull** (calvarium), followed by the femur, ribs, and mandible. Radiographically, these appear as "punched-out" lytic lesions without a sclerotic rim. In the mandible, it often causes the characteristic "floating teeth" appearance. **2. Why Other Options are Incorrect:** * **Skin:** This is the second most common site (approx. 30–40%). It often presents as a seborrheic dermatitis-like rash, particularly in infants (Letterer-Siwe disease). * **Lung:** While common in adult smokers (Pulmonary LCH), it is less frequent than bone involvement across the general population. * **Liver:** Involvement of the liver, spleen, or hematopoietic system signifies "high-risk" organ involvement and carries a poorer prognosis, but these are not the most common sites. **Clinical Pearls for NEET-PG:** * **Pathognomonic Marker:** **Birbeck granules** (tennis-racket shaped) seen on Electron Microscopy. * **Immunohistochemistry (IHC):** Positive for **CD1a, S100, and CD207 (Langerin)**. * **Hand-Schüller-Christian Triad:** Lytic bone lesions, exophthalmos, and diabetes insipidus. * **BRAF V600E mutation** is identified in about 50% of cases.

Q: Platelet transfusions must be completed within how many hours after the blood bag is issued from the blood bank?

4 hours. ### Explanation **Correct Answer: D. 4 hours** **Medical Rationale:** The primary reason for the strict 4-hour time limit for completing a platelet transfusion is the **risk of bacterial contamination**. Unlike Red Blood Cells (RBCs), which are stored at 2–6°C, platelets are stored at room temperature (20–24°C) with continuous agitation. This warmer environment is highly conducive to the rapid proliferation of bacteria. Once the blood bag is issued and the "cold chain" or controlled environment is breached, the risk of septic transfusion reactions increases significantly. To minimize this risk, international guidelines (including AABB and WHO) mandate that the infusion must be completed within 4 hours. **Analysis of Incorrect Options:** * **Option A (1 hour):** While platelets should be started as soon as possible (ideally within 30 minutes of issue), 1 hour is too restrictive for the total infusion time, especially in patients at risk of volume overload. * **Option B & C (2-3 hours):** Although most platelet transfusions are completed within 30–60 minutes, these timeframes do not represent the maximum safety limit established by transfusion medicine protocols. **High-Yield Clinical Pearls for NEET-PG:** * **Storage:** Platelets are stored at **20–24°C** with constant agitation to prevent aggregation and maintain viability. * **Shelf Life:** They have the shortest shelf life of all blood components, typically only **5 days**. * **Filter:** Must be administered through a standard **170–200 micron** filter. * **Dose Response:** One unit of random donor platelets (RDP) typically increases the platelet count by **5,000–10,000/µL** in a 70kg adult. * **Complication:** Platelets are the blood component most commonly associated with **transfusion-transmitted bacterial sepsis** [1].

Q: Which of the following investigations is least useful in the diagnosis of multiple myeloma?

Bone scan. The diagnosis of Multiple Myeloma (MM) relies on identifying monoclonal plasma cell proliferation and associated end-organ damage (CRAB features) [1]. **Why Bone Scan is the least useful:** In Multiple Myeloma, bone destruction is mediated by **osteoclast** activation and the inhibition of osteoblasts. A **Technetium-99m bone scan** detects areas of increased osteoblastic activity (bone formation). Because myeloma lesions are purely **lytic** (punched-out) with little to no osteoblastic reaction, bone scans often yield false-negative results. Therefore, they are not recommended for screening or diagnosis. **Analysis of other options:** * **X-ray (Skeletal Survey):** Traditionally the first-line imaging. It identifies classic "punched-out" lytic lesions, especially in the skull, spine, and pelvis [1]. * **Bone Marrow Biopsy:** A mandatory diagnostic tool. It confirms the presence of clonal plasma cells (≥10% required for diagnosis) and allows for cytogenetic studies (FISH) [1]. * **ESR:** While non-specific, ESR is almost always markedly elevated (often >100 mm/hr) in MM due to the "Rouleaux formation" caused by high levels of monoclonal paraproteins (M-spike) [1]. **NEET-PG High-Yield Pearls:** * **Imaging Gold Standard:** Whole-body low-dose CT (WBLDCT) or MRI is now preferred over X-ray for higher sensitivity. * **Mnemonic CRAB:** **C**alcium (elevated), **R**enal insufficiency, **A**nemia, **B**one lesions. * **Bence-Jones Proteins:** These are free light chains found in urine; they are *not* detected by standard dipsticks (which detect albumin). * **Diagnostic Hallmark:** Presence of **M-spike** on Serum Protein Electrophoresis (SPEP), usually in the Gamma globulin region.

Question 1

Which of the following agents is of value in the postoperative care of the hemophilic patient?

Accepted Answer

Aminocaproic acid

Answer

Vitamin K

Answer

Monsel's solution

Answer

Factor 8 cryoprecipitate

Question 2

A patient with a blood pressure of 90/60 mm Hg presents with pronounced cyanosis. Blood drawn from peripheral veins is observed to be chocolate brown in colour. What is the most likely diagnosis?

Accepted Answer

Methemoglobinemia

Answer

Hypovolemic shock

Answer

Cardiogenic shock

Answer

Hemorrhagic shock

Question 3

A 32-year-old male presents with abdominal pain and vomiting. He also complains of psychiatric symptoms and visual hallucinations. What is the most likely diagnosis?

Accepted Answer

Intermittent Porphyria

Answer

Hypothyroidism

Answer

Hyperthyroidism

Answer

Hysteria

Question 4

A patient presents with ecchymosis and petechiae all over the body, with no hepato-splenomegaly. All of the following are true regarding this condition EXCEPT:

Accepted Answer

Bleeding into the joints

Answer

Increased megakaryocytes in bone marrow

Answer

Decreased platelets in the blood

Answer

The disease resolves spontaneously in 80% of patients within 2-6 weeks

Question 5

A 25-year-old female presents with complaints of fever and weakness. On examination, there is splenomegaly of 3 cm below the costal margin. Her Hb is 8 gm/dL, TLC is 3,000/mm3, and platelet count is 80,000 mm3. Which of the following is the least likely diagnosis?

Accepted Answer

Aplastic anemia

Answer

Acute lymphocytic leukemia

Answer

Anemia of chronic disease

Answer

Megaloblastic anemia

Question 6

What is the basic defect in Hemoglobin S?

Accepted Answer

Altered solubility

Answer

Altered function

Answer

Altered stability

Answer

Altered oxygen binding capacity

Question 7

What is the most common site of histiocytosis?

Accepted Answer

Bone

Answer

Skin

Answer

Lung

Answer

Liver

Question 8

Platelet transfusions must be completed within how many hours after the blood bag is issued from the blood bank?

Accepted Answer

4 hours

Answer

1 hour

Answer

2 hours

Answer

3 hours

Question 9

A 65-year-old man presents with anaemia and posterior column dysfunction. What is the likely cause?

Accepted Answer

Vitamin B12 deficiency

Answer

Vitamin B1 deficiency

Answer

Subacute sclerosing panencephalitis

Answer

Multiple sclerosis

Question 10

Which of the following investigations is least useful in the diagnosis of multiple myeloma?

Accepted Answer

Bone scan

Answer

Erythrocyte Sedimentation Rate (ESR)

Answer

X-ray

Answer

Bone marrow biopsy

Hematology — MCQs

Hematology — MCQs

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