LE 6 REVIEW BOOK HEMA

Question 1

1. A 5-year-old child presents with petechiae and easy bruising following a recent viral infection. His platelet count is 30,000/µL. What is the most likely diagnosis?
   A. Heparin-induced thrombocytopenia (HIT)
   B. Immune thrombocytopenic purpura (ITP)
   C. Disseminated intravascular coagulation (DIC)
   D. Thrombotic thrombocytopenic purpura (TTP)

Answer 1

B. Immune thrombocytopenic purpura (ITP)

Rationale: ITP is the most common cause of thrombocytopenia in children, often following a viral infection. It is an autoimmune disorder where antibodies target platelets, leading to their destruction.

Question 2

2. A patient with cirrhosis and splenomegaly is found to have a platelet count of 90,000/µL. What is the most likely mechanism of thrombocytopenia in this patient?
   A. Increased platelet destruction
   B. Bone marrow failure
   C. Platelet sequestration
   D. Drug-induced thrombocytopenia

Answer 2

C. Platelet sequestration

Rationale: Splenomegaly leads to platelet sequestration, reducing circulating platelet count. This is commonly seen in liver cirrhosis.

Question 3

3. A hospitalized patient on heparin develops a drop in platelet count from 200,000/µL to 80,000/µL over 5 days. Which of the following is the most likely diagnosis?
   A. Heparin-induced thrombocytopenia (HIT)
   B. Thrombotic thrombocytopenic purpura (TTP)
   C. Disseminated intravascular coagulation (DIC)
   D. Immune thrombocytopenic purpura (ITP)

Answer 3

A. Heparin-induced thrombocytopenia (HIT)

Rationale: HIT is a prothrombotic disorder characterized by a drop in platelet count 5-10 days after heparin exposure. It paradoxically increases clotting risk rather than bleeding.

Question 4

4. Which of the following conditions causes both excessive clotting and bleeding due to widespread activation of coagulation pathways?
   A. Immune thrombocytopenic purpura (ITP)
   B. Disseminated intravascular coagulation (DIC)
   C. Essential thrombocythemia
   D. Von Willebrand disease

Answer 4

B. Disseminated intravascular coagulation (DIC)

Rationale: DIC results in widespread clot formation, leading to consumption of clotting factors and platelets, causing bleeding. It is seen in sepsis, trauma, and malignancies.

Question 5

5. A 60-year-old woman with anemia due to chronic gastrointestinal bleeding is found to have a platelet count of 600,000/µL. What is the most likely cause of her thrombocytosis?
   A. Polycythemia vera
   B. Essential thrombocythemia
   C. Reactive thrombocytosis
   D. Chronic myeloid leukemia

Answer 5

C. Reactive thrombocytosis

Rationale: Reactive thrombocytosis occurs secondary to conditions such as infection, inflammation, malignancy, or iron deficiency anemia.

Question 6

6. Essential thrombocythemia is associated with which of the following complications?
   A. Increased risk of clotting
   B. Increased risk of bleeding
   C. Both clotting and bleeding risk
   D. No significant complications

Answer 6

C. Both clotting and bleeding risk

Rationale: While thrombocytosis generally increases clotting risk, extremely high platelet counts (>1.5 million) can lead to bleeding due to acquired von Willebrand disease.

Question 7

7. A child with a history of easy bruising and mucosal bleeding has a defect in platelet aggregation due to the absence of Gp IIb/IIIa receptors. What is the most likely diagnosis?
   A. Bernard-Soulier Syndrome
   B. Glanzmann’s Thrombasthenia
   C. Von Willebrand Disease
   D. Storage Pool Disorder

Answer 7

B. Glanzmann’s Thrombasthenia

Rationale: Glanzmann’s Thrombasthenia is caused by a deficiency of the Gp IIb/IIIa receptor, leading to impaired platelet aggregation.

Question 8

8. A patient with a history of mucosal bleeding and prolonged bleeding time is found to have a defect in platelet adhesion due to an absence of Gp Ib-IX-V receptors. What is the most likely diagnosis?
   A. Bernard-Soulier Syndrome
   B. Glanzmann’s Thrombasthenia
   C. Von Willebrand Disease
   D. Heparin-induced thrombocytopenia

Answer 8

A. Bernard-Soulier Syndrome

Rationale: Bernard-Soulier Syndrome is due to the absence of the Gp Ib-IX-V receptor, leading to defective platelet adhesion.

Question 9

9. What is the most common inherited bleeding disorder that affects platelet adhesion?
   A. Glanzmann’s Thrombasthenia
   B. Bernard-Soulier Syndrome
   C. Von Willebrand Disease
   D. Storage Pool Disorder

Answer 9

C. Von Willebrand Disease

Rationale: Von Willebrand Disease (VWD) is the most common inherited bleeding disorder. It results from a deficiency or dysfunction of von Willebrand factor (vWF), which is necessary for platelet adhesion.

Question 10

10. A 65-year-old man on daily aspirin therapy for cardiovascular protection is found to have an increased bleeding tendency. What is the mechanism behind this?
    A. Decreased platelet production
    B. Inhibition of platelet aggregation
    C. Increased platelet sequestration
    D. Activation of coagulation pathways

Answer 10

B. Inhibition of platelet aggregation

Rationale: Aspirin irreversibly inhibits cyclooxygenase-1 (COX-1), preventing thromboxane A2 synthesis, which is essential for platelet aggregation.

Question 11

11. A patient with chronic kidney disease has a prolonged bleeding time despite a normal platelet count. What is the most likely cause of this patient’s bleeding tendency?
    A. Deficiency of clotting factors
    B. Platelet sequestration in the spleen
    C. Uremia-induced platelet dysfunction
    D. Immune thrombocytopenic purpura (ITP)

Answer 11

C. Uremia-induced platelet dysfunction

Rationale: Uremia in chronic kidney disease impairs platelet adhesion and activation, leading to prolonged bleeding time despite a normal platelet count.

Question 12

1. A 45-year-old man presents with recurrent episodes of epistaxis, GI bleeding, and visible telangiectasias on his lips and hands. He also has a family history of similar symptoms. What is the most likely diagnosis?
   A. Marfan Syndrome
   B. Hereditary Hemorrhagic Telangiectasia (HHT)
   C. Ehlers-Danlos Syndrome
   D. Scurvy

Answer 12

B. Hereditary Hemorrhagic Telangiectasia (HHT)

Rationale: HHT (Osler-Weber-Rendu syndrome) is an inherited disorder that leads to defective capillaries, causing telangiectasias, epistaxis, and GI bleeding. Arteriovenous malformations (AVMs) in the lungs, brain, and liver are also common.

Question 13

2. A 32-year-old woman with a history of hyperflexible joints and easy bruising presents with spontaneous bruises on her legs. She has hyperelastic skin and a history of mitral valve prolapse. What is the most likely diagnosis?
   A. Marfan Syndrome
   B. Hereditary Hemorrhagic Telangiectasia
   C. Ehlers-Danlos Syndrome
   D. Scurvy

Answer 13

C. Ehlers-Danlos Syndrome

Rationale: Ehlers-Danlos Syndrome (EDS) is a connective tissue disorder caused by defective collagen synthesis. It leads to hyperelastic skin, hypermobile joints, vessel fragility, and easy bruising.

Question 14

3. A 25-year-old tall male with long limbs and a history of lens dislocation presents with aortic root dilation and easy bruising. Which of the following best explains his vascular disorder?
   A. Defective fibrillin-1 protein
   B. Deficiency of vitamin C
   C. Dysfunctional von Willebrand factor
   D. Decreased platelet count

Answer 14

A. Defective fibrillin-1 protein

Rationale: Marfan Syndrome is caused by mutations in the FBN1 gene, which encodes fibrillin-1, a key component of connective tissue. It affects large vessels, leading to aortic root dilation and dissection.

Question 15

4. A 60-year-old man with a diet deficient in fruits and vegetables presents with bleeding gums, perifollicular hemorrhages, and corkscrew hair. Which of the following is the most likely underlying deficiency?
   A. Vitamin B12
   B. Vitamin C
   C. Vitamin K
   D. Iron

Answer 15

B. Vitamin C

Rationale: Scurvy is caused by vitamin C deficiency, leading to impaired collagen synthesis, resulting in fragile blood vessels, gingival bleeding, and perifollicular hemorrhages.

Question 16

5. A 68-year-old woman presents with recurrent ecchymoses on her forearms without a history of trauma. Her skin appears thin and fragile. She has no platelet abnormalities. What is the most likely diagnosis?
   A. Senile Purpura
   B. Disseminated Intravascular Coagulation (DIC)
   C. Heparin-Induced Thrombocytopenia (HIT)
   D. Ehlers-Danlos Syndrome

Answer 16

A. Senile Purpura

Rationale: Senile purpura is a benign condition seen in elderly individuals due to age-related capillary fragility and atrophy of the dermis. It is common on sun-exposed areas such as the forearms.

Question 17

6. A patient on long-term corticosteroid therapy develops easy bruising and thinning of the skin. What is the mechanism behind this vascular disorder?
   A. Impaired platelet function
   B. Inhibition of vitamin K-dependent clotting factors
   C. Atrophy of connective tissue supporting blood vessels
   D. Increased vascular inflammation

Answer 17

C. Atrophy of connective tissue supporting blood vessels

Rationale: Chronic corticosteroid use (as seen in Cushing’s Syndrome) leads to connective tissue atrophy, making blood vessels more fragile and prone to easy bruising.

Question 18

7. A peripheral blood smear shows giant platelets. This finding is characteristic of which disorder?
   A. Glanzmann’s Thrombasthenia
   B. Bernard-Soulier Syndrome
   C. Immune Thrombocytopenic Purpura (ITP)
   D. Disseminated Intravascular Coagulation (DIC)

Answer 18

B. Bernard-Soulier Syndrome

Rationale: Giant platelets are characteristic of Bernard-Soulier Syndrome, a platelet adhesion disorder due to a deficiency of Gp Ib-IX-V receptors.

Question 19

8. A patient presents with thrombocytopenia, microangiopathic hemolytic anemia, and schistocytes on a peripheral smear. What is the most likely diagnosis?
   A. Disseminated Intravascular Coagulation (DIC)
   B. Thrombotic Thrombocytopenic Purpura (TTP)
   C. Immune Thrombocytopenic Purpura (ITP)
   D. Bernard-Soulier Syndrome

Answer 19

B. Thrombotic Thrombocytopenic Purpura (TTP)

Rationale: Schistocytes (fragmented RBCs) suggest microangiopathic hemolytic anemia, which occurs in TTP, DIC, and Hemolytic Uremic Syndrome (HUS). TTP is associated with thrombocytopenia, fever, neurological symptoms, renal dysfunction, and microangiopathic hemolytic anemia.

Question 20

9. A platelet function test reveals an abnormal ristocetin test. Which of the following is the most likely diagnosis?
   A. Bernard-Soulier Syndrome
   B. Glanzmann’s Thrombasthenia
   C. Von Willebrand Disease
   D. Heparin-Induced Thrombocytopenia

Answer 20

C. Von Willebrand Disease

Rationale: An abnormal ristocetin test suggests von Willebrand Disease (VWD), a disorder affecting platelet adhesion due to vWF deficiency or dysfunction.

Question 21

10. A platelet aggregation test shows an absence of aggregation with ADP and collagen but normal response to ristocetin. Which disorder does this indicate?
    A. Bernard-Soulier Syndrome
    B. Glanzmann’s Thrombasthenia
    C. Von Willebrand Disease
    D. Disseminated Intravascular Coagulation (DIC)

Answer 21

B. Glanzmann’s Thrombasthenia

Rationale: Glanzmann’s Thrombasthenia is a platelet aggregation disorder caused by a deficiency of Gp IIb/IIIa receptors. It results in absent aggregation with ADP and collagen but normal response to ristocetin.

Question 22

11. A bone marrow biopsy of a patient with pancytopenia shows hypocellular marrow. What is the most likely diagnosis?
    A. Myelodysplastic Syndrome
    B. Aplastic Anemia
    C. Disseminated Intravascular Coagulation
    D. Polycythemia Vera

Answer 22

B. Aplastic Anemia

Rationale: Aplastic anemia presents with pancytopenia and hypocellular bone marrow due to failure of hematopoiesis, often caused by autoimmune destruction or toxins.

Question 23

1. A 5-year-old boy with recurrent painful episodes and jaundice presents with anemia and a peripheral smear showing sickle-shaped red blood cells. What is the underlying molecular defect?
   A. Glu6Lys mutation in β-globin
   B. Glu6Val mutation in β-globin
   C. β-globin mutation affecting splicing
   D. α-globin gene deletion

Answer 23

B. Glu6Val mutation in β-globin

Rationale: Sickle cell disease (SCD) results from a Glu6Val mutation in the β-globin gene, leading to HbS polymerization under deoxygenated conditions, causing RBC sickling.

Question 24

2. A patient with sickle cell disease presents with acute-onset chest pain, dyspnea, and fever. Chest X-ray shows pulmonary infiltrates. What is the most likely diagnosis?
   A. Acute chest syndrome
   B. Pulmonary embolism
   C. Bacterial pneumonia
   D. Mycoplasma pneumonia

Answer 24

A. Acute chest syndrome

Rationale: Acute chest syndrome (ACS) is a leading cause of mortality in sickle cell disease. It is triggered by vaso-occlusion in pulmonary vasculature, infections, or fat emboli.

Question 25

3. Which of the following is the first-line treatment for sickle cell disease to increase HbF levels? A. Methotrexate B. Hydroxyurea C. Erythropoietin D. Prednisone

Answer 25

B. Hydroxyurea Rationale: Hydroxyurea increases fetal hemoglobin (HbF), which inhibits HbS polymerization, reducing sickling and vaso-occlusive crises in sickle cell disease.

Question 26

4. A patient’s hemoglobin electrophoresis shows >90% HbS. Which of the following is the most likely diagnosis? A. Sickle cell trait B. Sickle cell disease (HbSS) C. HbSC disease D. Hemoglobin C disease

Answer 26

B. Sickle cell disease (HbSS) Rationale: HbS >90% on electrophoresis is diagnostic for sickle cell disease (HbSS), whereas sickle cell trait (HbAS) has <50% HbS.

Question 27

5. A 28-year-old African American man is found to have hemoglobin C disease on electrophoresis. Which characteristic finding is expected on his peripheral blood smear? A. Sickle cells B. Bite cells C. Target cells D. Acanthocytes

Answer 27

C. Target cells Rationale: HbC disease is characterized by target cells and mild hemolytic anemia. It results from a Glu6Lys mutation in β-globin.

Question 28

9. A 24-year-old man develops hemolysis after eating fava beans. Peripheral smear shows bite cells and Heinz bodies. What is the underlying mechanism? A. Increased oxidative stress B. Reduced hemoglobin synthesis C. Impaired oxygen binding D. Defective globin chain production

Answer 28

A. Increased oxidative stress Rationale: Heinz body hemolytic anemia occurs when unstable hemoglobins or G6PD deficiency lead to oxidative damage, causing RBCs to form Heinz bodies and undergo extravascular hemolysis.

Question 29

10. A 3-year-old child presents with cyanosis and chocolate-colored blood. Pulse oximetry is low, but oxygen therapy does not improve his symptoms. What is the most likely diagnosis? A. Carboxyhemoglobinemia B. Methemoglobinemia C. Sickle cell disease D. Hemoglobin E disease

Answer 29

B. Methemoglobinemia Rationale: Methemoglobinemia occurs when hemoglobin’s iron is oxidized to Fe³⁺ (ferric form), which cannot bind oxygen, leading to cyanosis and brownish blood.

Question 30

1. A 25-year-old woman of Southeast Asian descent presents with mild anemia and microcytosis but has a normal iron panel. Hemoglobin electrophoresis is unremarkable. What is the most likely diagnosis? A. Beta thalassemia minor B. Alpha thalassemia trait C. Iron deficiency anemia D. Sideroblastic anemia

Answer 30

B. Alpha thalassemia trait Rationale: Alpha thalassemia trait (-α/-α or --/αα) presents with mild microcytic anemia but normal iron studies. Unlike beta thalassemia minor, Hb electrophoresis is often normal.

Question 31

2. A newborn presents with hydrops fetalis and is found to have Hemoglobin Bart’s (γ₄) on hemoglobin electrophoresis. What is the underlying genetic defect? A. Deletion of all four α-globin genes B. Mutation in the β-globin gene C. Increased γ-globin chain production D. Hemoglobin instability

Answer 31

A. Deletion of all four α-globin genes Rationale: Hydrops fetalis (Hb Bart’s) results from complete deletion of α-globin genes (--/--), leading to γ₄ tetramers, which cannot carry oxygen.

Question 32

4. A 2-year-old Mediterranean boy presents with pallor, hepatosplenomegaly, and growth retardation. Labs show severe microcytic anemia, target cells, and nucleated RBCs. Hemoglobin electrophoresis shows absent HbA and increased HbF. What is the most likely diagnosis? A. Beta thalassemia minor B. Beta thalassemia major C. Alpha thalassemia trait D. Hemoglobin H disease

Answer 32

B. Beta thalassemia major Rationale: Beta thalassemia major (Cooley’s anemia, β⁰/β⁰) results in severe anemia, hepatosplenomegaly, and absent HbA with increased HbF.

Question 33

6. A 10-year-old boy with beta thalassemia major has received frequent blood transfusions. Which of the following complications is most concerning? A. Hemarthrosis B. Iron overload (hemochromatosis) C. Hemoglobinuria D. Splenic rupture

Answer 33

B. Iron overload (hemochromatosis) Rationale: Frequent transfusions in beta thalassemia major can cause iron overload, requiring iron chelation therapy (e.g., deferasirox, deferoxamine).

Question 34

7. A skull X-ray of a child with beta thalassemia major shows a "crew-cut" appearance. What is the underlying cause? A. Skull fractures B. Extramedullary hematopoiesis C. Hemoglobin instability D. Iron deficiency

Answer 34

B. Extramedullary hematopoiesis Rationale: The "crew-cut" skull appearance results from marrow expansion due to chronic anemia, leading to extramedullary hematopoiesis.

Question 35

8. Which of the following is the most definitive treatment for beta thalassemia major? A. Lifelong transfusions B. Hydroxyurea C. Bone marrow transplantation D. Iron chelation therapy

Answer 35

C. Bone marrow transplantation Rationale: Bone marrow transplantation is the only curative treatment for beta thalassemia major, though lifelong transfusions and iron chelation are the mainstays of management.

Question 36

1. A 25-year-old man with sickle cell disease has mild symptoms despite having HbSS on genetic testing. Hemoglobin electrophoresis shows elevated HbF levels. What is the most likely explanation for his milder disease course? A. Coinheritance of alpha thalassemia B. Hereditary Persistence of Fetal Hemoglobin (HPFH) C. Iron deficiency anemia D. Sideroblastic anemia

Answer 36

B. Hereditary Persistence of Fetal Hemoglobin (HPFH) Rationale: HPFH results from HBB cluster deletions, leading to persistent fetal hemoglobin (HbF, α₂γ₂) production, which inhibits HbS polymerization and reduces sickling episodes.

Question 37

4. A firefighter presents with headache, dizziness, and cherry-red skin after being in a burning building. What is the most likely diagnosis? A. Methemoglobinemia B. Carboxyhemoglobinemia C. Sulfhemoglobinemia D. Sickle cell crisis

Answer 37

B. Carboxyhemoglobinemia Rationale: CO poisoning occurs due to CO binding to Hb with high affinity, impairing oxygen transport. Classic signs include cherry-red skin, headache, dizziness.

Question 38

9. Which of the following is the most common hemoglobinopathy worldwide? A. Sickle Cell Disease (HbS) B. Beta Thalassemia C. Alpha Thalassemia Trait D. Hemoglobin E (HbE)

Answer 38

D. Hemoglobin E (HbE) Rationale: HbE is the most common hemoglobin variant worldwide, especially in Southeast Asia.

Question 39

10. The most common thalassemia globally is: A. Alpha thalassemia trait B. Beta thalassemia major C. Beta thalassemia minor D. Hemoglobin H disease

Answer 39

B. Beta thalassemia major Rationale: Beta thalassemia major is the most common severe thalassemia, requiring lifelong transfusions.

Question 40

11. The most common cause of microcytic anemia worldwide is: A. Iron deficiency anemia B. Alpha thalassemia trait C. Beta thalassemia minor D. Anemia of chronic disease

Answer 40

A. Iron deficiency anemia Rationale: Iron deficiency anemia is the most common cause of microcytic anemia, but in Southeast Asia, alpha thalassemia trait is a frequent cause.

Question 41

12. The most common cause of microcytic anemia in Southeast Asia is: A. Iron deficiency anemia B. Beta thalassemia minor C. Alpha thalassemia trait D. Hemoglobin H disease

Answer 41

C. Alpha thalassemia trait Rationale: Alpha thalassemia trait is highly prevalent in Southeast Asia and causes mild microcytosis.

Question 42

1. Which of the following is NOT a common cause of iron deficiency anemia? A. Chronic gastrointestinal bleeding B. Heavy menstruation C. Increased erythropoiesis during pregnancy D. Hemolysis due to G6PD deficiency

Answer 42

D. Hemolysis due to G6PD deficiency Rationale: Hemolysis in G6PD deficiency does not lead to iron deficiency anemia because iron from lysed RBCs is recycled. Chronic blood loss, pregnancy, and menstruation are common causes of IDA.

Question 43

2. A 45-year-old male presents with iron deficiency anemia but denies any history of blood loss. Which underlying condition should be ruled out first? A. Peptic ulcer disease B. Colon cancer C. Helicobacter pylori infection D. Vitamin B12 deficiency

Answer 43

B. Colon cancer Rationale: Occult gastrointestinal (GI) bleeding, especially from colon cancer, is a common cause of iron deficiency anemia in adult males and postmenopausal women.

Question 44

3. A patient with Crohn’s disease and chronic diarrhea is found to have microcytic anemia. What is the most likely mechanism of their anemia? A. Increased blood loss B. Impaired iron absorption C. Increased iron demand D. Hemolysis

Answer 44

B. Impaired iron absorption Rationale: Crohn’s disease affects the small intestine, impairing iron absorption, leading to iron deficiency anemia.

Question 45

4. In the early stage of iron deficiency (negative iron balance), which laboratory abnormality is expected? A. Low serum ferritin B. Low hemoglobin C. Increased mean corpuscular volume (MCV) D. Increased serum iron

Answer 45

A. Low serum ferritin Rationale: Serum ferritin (<15 µg/L) is the earliest marker of iron depletion, occurring before changes in serum iron or hemoglobin.

Question 46

5. A patient's lab results show: Low serum iron (<30 µg/dL) Increased total iron-binding capacity (TIBC >360 µg/dL) Transferrin saturation <15% Which stage of iron deficiency is this patient in? A. Negative iron balance B. Iron-deficient erythropoiesis C. Iron deficiency anemia D. Megaloblastic anemia

Answer 46

B. Iron-deficient erythropoiesis Rationale: In iron-deficient erythropoiesis, iron levels are low, TIBC is increased, and transferrin saturation drops, but hemoglobin levels remain normal. TRANSFERRIN SATURATION: 20-15-10% -> IDA

Question 47

6. A peripheral blood smear of a patient with severe iron deficiency anemia is most likely to show which characteristic feature? A. Macrocytic RBCs B. Howell-Jolly bodies C. Poikilocytes (pencil/cigar-shaped cells) D. Heinz bodies

Answer 47

C. Poikilocytes (pencil/cigar-shaped cells) Rationale: Iron deficiency anemia is associated with microcytic, hypochromic RBCs and pencil-shaped cells.

Question 48

7. A 32-year-old woman presents with fatigue, pallor, and a craving for ice. She is most likely suffering from which of the following? A. Vitamin B12 deficiency B. Iron deficiency anemia C. Thalassemia minor D. Lead poisoning

Answer 48

B. Iron deficiency anemia Rationale: Pica (craving for ice, dirt, clay) is a classic symptom of iron deficiency anemia.

Question 49

8. Which of the following is a unique symptom of iron deficiency anemia that is not typically seen in other causes of anemia? A. Fatigue and pallor B. Koilonychia (spoon nails) C. Glossitis D. Tachycardia

Answer 49

B. Koilonychia (spoon nails) Rationale: Koilonychia (spoon-shaped nails) is a classic sign of iron deficiency anemia, reflecting tissue hypoxia.

Question 50

9. A patient with chronic iron deficiency anemia presents with dysphagia and esophageal webs. What is the most likely diagnosis? A. Wilson’s disease B. Plummer-Vinson syndrome C. Sjögren’s syndrome D. Peutz-Jeghers syndrome

Answer 50

B. Plummer-Vinson syndrome Rationale: Plummer-Vinson syndrome is a triad of iron deficiency anemia, dysphagia, and esophageal webs.

Question 51

10. A patient with long-standing iron deficiency anemia reports an uncomfortable sensation in her legs at night, relieved by movement. Which of the following is the most likely diagnosis? A. Peripheral neuropathy B. Restless leg syndrome C. Fibromyalgia D. Vitamin B12 deficiency

Answer 51

B. Restless leg syndrome Rationale: Restless leg syndrome is associated with iron deficiency anemia, likely due to dopaminergic dysfunction.

Question 52

1. A 65-year-old woman with rheumatoid arthritis presents with fatigue and pallor. Her lab results show: Serum iron: ↓ TIBC: ↓ Ferritin: Normal/↑ MCV: Normal What is the most likely diagnosis? A. Iron deficiency anemia B. Anemia of chronic disease C. Beta thalassemia minor D. Anemia of chronic kidney disease

Answer 52

B. Anemia of chronic disease Rationale: Anemia of chronic disease (ACD) is caused by increased hepcidin, leading to low iron, low TIBC, and normal or increased ferritin.

Question 53

2. Which of the following best explains the pathophysiology of anemia of chronic inflammation? A. Increased erythropoietin production B. Decreased iron absorption from the intestine C. Increased hepcidin blocking iron release from macrophages D. Increased red blood cell (RBC) destruction

Answer 53

C. Increased hepcidin blocking iron release from macrophages Rationale: Hepcidin, stimulated by IL-6, inhibits ferroportin, preventing iron release from macrophages and enterocytes, reducing iron availability for erythropoiesis.

Question 54

4. A 58-year-old male with chronic kidney disease stage 4 presents with anemia. Which of the following is the primary cause of his anemia? A. Increased hepcidin production B. Erythropoietin (EPO) deficiency C. Increased RBC destruction D. Iron overload

Answer 54

B. Erythropoietin (EPO) deficiency Rationale: CKD leads to decreased EPO production by the kidneys, resulting in reduced RBC production and normocytic anemia.

Question 55

6. A 65-year-old CKD patient on hemodialysis develops worsening anemia. Which of the following is the most appropriate treatment? A. Oral iron supplements B. IV iron therapy C. Blood transfusions D. High-dose erythropoietin

Answer 55

B. IV iron therapy Rationale: Hemodialysis patients often have functional iron deficiency due to iron losses, requiring IV iron therapy rather than oral supplementation.

Question 56

7. A 50-year-old woman with fatigue and weight gain is diagnosed with hypothyroidism. Her lab results show: Hb: 10.2 g/dL (low) MCV: Normal Reticulocyte count: Low TSH: High T4: Low What is the most likely cause of her anemia? A. Iron deficiency anemia B. Anemia of chronic disease C. Hypometabolic anemia due to hypothyroidism D. Beta thalassemia minor

Answer 56

C. Hypometabolic anemia due to hypothyroidism Rationale: Hypothyroidism leads to reduced erythropoiesis due to low EPO levels, causing normocytic anemia with a low reticulocyte count.

Question 57

1. What is the most common leukemia in children, peaking at 3-4 years old? A. Acute Myeloid Leukemia (AML) B. Chronic Myeloid Leukemia (CML) C. Acute Lymphoblastic Leukemia (ALL) D. Chronic Lymphocytic Leukemia (CLL)

Answer 57

C. Acute Lymphoblastic Leukemia (ALL) Rationale: ALL is the most common childhood leukemia, peaking at 3-4 years of age, with a high cure rate in children.

Question 58

2. Which cytogenetic abnormality is most commonly associated with older patients with B-lineage ALL? A. t(9;22) (Philadelphia chromosome, BCR-ABL1) B. t(15;17) (PML-RARA) C. t(8;21) (RUNX1-RUNX1T1) D. JAK2 mutation

Answer 58

A. t(9;22) (Philadelphia chromosome, BCR-ABL1) Rationale: The Philadelphia chromosome (BCR-ABL1) is more common in older adults and associated with poorer prognosis.

Question 59

3. A child with ALL presents with pallor, petechiae, and recurrent infections. Which of the following best explains these findings? A. Organ infiltration B. Bone marrow failure C. Hemolysis D. Vitamin B12 deficiency

Answer 59

B. Bone marrow failure Rationale: Bone marrow infiltration by leukemic blasts leads to anemia (pallor, fatigue), thrombocytopenia (bleeding, petechiae), and neutropenia (recurrent infections).

Question 60

4. A patient with ALL presents with headaches, vomiting, and cranial nerve palsies. What is the most likely cause? A. Hyperleukocytosis B. Meningeal leukemia (CNS involvement) C. Chemotherapy-induced neurotoxicity D. Metastatic disease

Answer 60

B. Meningeal leukemia (CNS involvement) Rationale: CNS involvement is a hallmark of ALL, requiring intrathecal chemotherapy for prophylaxis.

Question 61

8. Which of the following is the gold standard for confirming the diagnosis of ALL? A. Peripheral blood smear B. Flow cytometry C. Bone marrow biopsy D. Serum LDH levels

Answer 61

C. Bone marrow biopsy Rationale: Bone marrow biopsy is required to confirm ALL, identify blast percentage, and classify the lineage.

Question 62

9. Which of the following drugs is a tyrosine kinase inhibitor (TKI) used in Philadelphia chromosome-positive ALL? A. Rituximab B. Imatinib C. Methotrexate D. Cytarabine

Answer 62

B. Imatinib Rationale: Imatinib is a first-line TKI for Ph+ ALL. Other TKIs include Dasatinib and Nilotinib.

Question 63

11. The most common site of relapse in ALL is: A. Bone marrow B. CNS C. Testes D. Liver

Answer 63

A. Bone marrow Rationale: Bone marrow is the most common relapse site, followed by CNS and testes.

Question 64

12. Which of the following is a poor prognostic factor in ALL? A. Age 2-10 years B. WBC count <10,000/µL at diagnosis C. Minimal residual disease (MRD) positivity post-induction D. Presence of t(12;21) translocation

Answer 64

C. Minimal residual disease (MRD) positivity post-induction Rationale: MRD positivity after induction is a strong predictor of relapse and poor prognosis.

Question 65

14. What is the approximate cure rate for childhood ALL with modern therapy? A. 50% B. 70% C. 90% D. 30%

Answer 65

C. 90% Rationale: Advances in treatment have increased childhood ALL cure rates to ~90%.

Question 66

15. Which of the following groups has the poorest survival rate in ALL? A. Children (1-10 years) B. Adolescents (15-25 years) C. Adults 45-55 years D. Elderly (>55 years)

Answer 66

D. Elderly (>55 years) Rationale: Elderly patients (>55 years) have a <30% survival rate due to poor treatment tolerance and high-risk cytogenetics.

Question 67

1. What is the most common leukemia in adults in Western countries? A. Acute Myeloid Leukemia (AML) B. Chronic Myeloid Leukemia (CML) C. Chronic Lymphocytic Leukemia (CLL) D. Acute Lymphoblastic Leukemia (ALL)

Answer 67

C. Chronic Lymphocytic Leukemia (CLL) Rationale: CLL is the most common leukemia in adults in Western countries, with a median diagnosis age of 71 years.

Question 68

3. What is the most common initial presentation of CLL? A. Recurrent infections B. Lymphadenopathy C. Incidentally discovered lymphocytosis D. Splenomegaly

Answer 68

C. Incidentally discovered lymphocytosis Rationale: Most CLL cases are asymptomatic and diagnosed incidentally on routine blood work showing lymphocytosis (>5000 B cells/µL).

Question 69

4. Which of the following symptoms in a patient with CLL indicates disease progression? A. Lymphocytosis B. Night sweats and weight loss C. Mild thrombocytopenia D. Fatigue

Answer 69

B. Night sweats and weight loss Rationale: B symptoms (fever, night sweats, weight loss) suggest advanced CLL and may indicate the need for treatment.

Question 70

5. Which of the following cytogenetic abnormalities is associated with a favorable prognosis in CLL? A. del(13q) B. del(17p) C. trisomy 12 D. del(11q)

Answer 70

A. del(13q) Rationale: del(13q) (55%) is the most common cytogenetic abnormality in CLL and is associated with a favorable prognosis.

Question 71

8. In the Rai staging system, what feature defines Stage IV CLL? A. Lymphocytosis only B. Lymphocytosis with lymphadenopathy C. Lymphocytosis with splenomegaly D. Lymphocytosis with thrombocytopenia (<100,000/µL)

Answer 71

D. Lymphocytosis with thrombocytopenia (<100,000/µL) Rationale: Stage IV CLL in the Rai staging system is defined by lymphocytosis with thrombocytopenia (<100,000/µL) and is considered high-risk.

Question 72

9. A patient with CLL presents with rapid lymphocyte doubling time, hemoglobin 9.5 g/dL, and bulky lymphadenopathy. What is the next best step? A. Observation B. Start targeted therapy C. Bone marrow biopsy D. Intravenous immunoglobulin (IVIG)

Answer 72

B. Start targeted therapy Rationale: Indications for CLL treatment include rapid lymphocyte doubling (<6 months), symptomatic splenomegaly, cytopenias, and autoimmune complications.

Question 73

10. Which of the following is a first-line therapy for most patients with CLL? A. Fludarabine + Cyclophosphamide + Rituximab (FCR) B. Ibrutinib C. Methotrexate D. Hydroxyurea

Answer 73

B. Ibrutinib Rationale: Ibrutinib (a BTK inhibitor) is preferred for most CLL patients, while FCR is used in select young, fit patients.

Question 74

13. What is the most common cause of death in CLL patients? A. Infection B. Richter’s transformation C. Bone marrow failure D. Secondary malignancies

Answer 74

A. Infection Rationale: Hypogammaglobulinemia and neutropenia in CLL lead to recurrent infections, the leading cause of death (~50%).

Question 75

14. A patient with CLL develops sudden worsening of lymphadenopathy and high-grade fever. Biopsy confirms large B-cell lymphoma. What is the diagnosis? A. Autoimmune hemolytic anemia B. Richter’s transformation C. Hodgkin lymphoma D. CML blast crisis

Answer 75

B. Richter’s transformation Rationale: Richter’s transformation is the progression of CLL to aggressive Diffuse Large B-cell Lymphoma (DLBCL) with poor prognosis.

Question 76

1. Which of the following is the most common hematologic malignancy in adults? A. Acute Myeloid Leukemia (AML) B. Chronic Myeloid Leukemia (CML) C. Hodgkin’s Lymphoma (HL) D. Non-Hodgkin’s Lymphoma (NHL)

Answer 76

D. Non-Hodgkin’s Lymphoma (NHL) Rationale: NHL is the most common hematologic malignancy in adults and is 10 times more common than Hodgkin’s lymphoma (HL).

Question 77

2. Which of the following is true regarding the epidemiology of NHL? A. More common in females B. Incidence peaks in childhood C. More common in Caucasians and increases with age D. Less common than Hodgkin’s lymphoma

Answer 77

C. More common in Caucasians and increases with age Rationale: NHL has a slight male predominance, is more common in Caucasians, and increases in incidence after age 40.

Question 78

3. Epstein-Barr virus (EBV) infection is strongly associated with which subtype of NHL? A. Diffuse Large B-cell Lymphoma (DLBCL) B. Follicular Lymphoma C. Burkitt’s Lymphoma D. Marginal Zone Lymphoma

Answer 78

C. Burkitt’s Lymphoma Rationale: EBV infection is associated with Burkitt’s lymphoma, particularly in endemic (African) cases.

Question 79

4. Which of the following infections is most strongly associated with gastric MALT lymphoma? A. Epstein-Barr Virus (EBV) B. Human T-cell Leukemia Virus-1 (HTLV-1) C. Helicobacter pylori D. Hepatitis C

Answer 79

C. Helicobacter pylori Rationale: Helicobacter pylori infection is a well-known risk factor for gastric MALT lymphoma, and eradication therapy can lead to remission.

Question 80

5. Which of the following conditions is a strong risk factor for developing NHL? A. Rheumatoid arthritis B. Sjögren’s syndrome C. Hashimoto’s thyroiditis D. All of the above

Answer 80

D. All of the above Rationale: Autoimmune diseases such as Sjögren’s syndrome and Hashimoto’s thyroiditis increase the risk of NHL, particularly marginal zone lymphomas.

Question 81

6. What is the most common clinical presentation of NHL? A. Painful lymphadenopathy B. Painless lymphadenopathy C. B symptoms only D. Hepatosplenomegaly without lymphadenopathy

Answer 81

B. Painless lymphadenopathy Rationale: Painless lymphadenopathy is the most common presentation of NHL and is frequently detected in the cervical, axillary, or inguinal lymph nodes.

Question 82

7. A patient with NHL presents with fever, night sweats, and weight loss. These symptoms indicate: A. Low-grade NHL B. Indolent lymphoma C. B symptoms, suggesting an aggressive lymphoma D. Localized disease with an excellent prognosis

Answer 82

C. B symptoms, suggesting an aggressive lymphoma Rationale: B symptoms (fever >38°C, night sweats, weight loss >10% in 6 months) indicate more aggressive NHL subtypes.

Question 83

8. Which aggressive form of NHL frequently presents as a rapidly enlarging mass? A. Diffuse Large B-cell Lymphoma (DLBCL) B. Follicular Lymphoma C. Small Lymphocytic Lymphoma (SLL) D. Marginal Zone Lymphoma

Answer 83

A. Diffuse Large B-cell Lymphoma (DLBCL) Rationale: DLBCL is an aggressive lymphoma that often presents as a rapidly growing mass, commonly extranodal.

Question 84

9. What is the gold standard for diagnosing NHL? A. Peripheral blood smear B. Bone marrow biopsy C. Lymph node biopsy D. Serum electrophoresis

Answer 84

C. Lymph node biopsy Rationale: Lymph node biopsy is required for definitive diagnosis and classification of NHL subtypes.

Question 85

10. Which of the following translocations is associated with Follicular Lymphoma? A. t(8;14) MYC translocation B. t(14;18) BCL2 translocation C. t(11;14) Cyclin D1 translocation D. del(17p)

Answer 85

B. t(14;18) BCL2 translocation Rationale: Follicular lymphoma is characterized by the t(14;18) translocation, leading to BCL2 overexpression, which prevents apoptosis.

Question 86

11. Burkitt’s lymphoma is characterized by which genetic translocation? A. t(14;18) BCL2 translocation B. t(11;14) Cyclin D1 translocation C. t(8;14) MYC translocation D. t(9;22) BCR-ABL1

Answer 86

C. t(8;14) MYC translocation Rationale: Burkitt’s lymphoma is driven by the t(8;14) MYC translocation, leading to rapidly proliferating tumor growth.

Question 87

12. Which of the following is the first-line chemotherapy regimen for aggressive NHL, including DLBCL? A. ABVD B. R-CHOP C. FCR D. Methotrexate

Answer 87

B. R-CHOP Rationale: R-CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, Prednisone) is the standard first-line regimen for aggressive B-cell NHLs.

Question 88

13. In patients with relapsed or refractory NHL, which of the following advanced therapies may be considered? A. CAR-T cell therapy B. Tyrosine kinase inhibitors C. Hydroxyurea D. Low-dose steroids

Answer 88

A. CAR-T cell therapy Rationale: CAR-T cell therapy (Chimeric Antigen Receptor T-cell therapy) is used for refractory or relapsed aggressive NHL.

Question 89

1. Hodgkin’s lymphoma (HL) is characterized by which of the following epidemiological patterns? A. Occurs primarily in children under 5 years old B. Has a bimodal age distribution C. More common in women than men D. Has an equal incidence across all age groups

Answer 89

B. Has a bimodal age distribution Rationale: HL exhibits a bimodal age distribution, with peaks in young adults (15-30 years) and the elderly (>55 years).

Question 90

3. Which virus is found in ~40% of Hodgkin’s lymphoma cases and is strongly associated with the mixed cellularity subtype? A. Human T-cell Leukemia Virus-1 (HTLV-1) B. Epstein-Barr Virus (EBV) C. Hepatitis C Virus (HCV) D. Human Papillomavirus (HPV)

Answer 90

B. Epstein-Barr Virus (EBV) Rationale: EBV infection is linked to ~40% of HL cases, particularly mixed cellularity HL, and is more common in HIV-positive individuals.

Question 91

4. Which of the following conditions is associated with an increased risk of developing Hodgkin’s lymphoma? A. Type 1 Diabetes Mellitus B. Systemic Lupus Erythematosus C. HIV/AIDS D. Ulcerative Colitis

Answer 91

C. HIV/AIDS Rationale: HIV/AIDS increases the risk of developing HL, particularly mixed cellularity HL.

Question 92

5. Which subtype of Hodgkin’s lymphoma is the most common? A. Mixed Cellularity HL (MCHL) B. Nodular Sclerosis HL (NSHL) C. Lymphocyte-Rich HL (LRHL) D. Lymphocyte-Depleted HL (LDHL)

Answer 92

B. Nodular Sclerosis HL (NSHL) Rationale: NSHL is the most common subtype (~70%) and frequently presents with a mediastinal mass in young adults.

Question 93

10. Which characteristic cell type is seen in Hodgkin’s lymphoma? A. Auer rods B. Reed-Sternberg cells C. Smudge cells D. Sézary cells

Answer 93

B. Reed-Sternberg cells Rationale: Reed-Sternberg cells (binucleated "Owl’s eye" cells) are pathognomonic for Hodgkin’s lymphoma.

Question 94

11. A patient with HL has lymph node involvement in both the cervical and axillary regions on the same side of the diaphragm. What is the correct Ann Arbor stage? A. Stage I B. Stage II C. Stage III D. Stage IV

Answer 94

B. Stage II Rationale: Stage II HL involves two or more lymph node regions on the same side of the diaphragm.

Question 95

12. What is the first-line chemotherapy regimen for Hodgkin’s lymphoma? A. CHOP B. BEACOPP C. ABVD D. R-CHOP

Answer 95

C. ABVD Rationale: ABVD (Adriamycin, Bleomycin, Vinblastine, Dacarbazine) is the standard first-line regimen for HL.

Question 96

13. Which treatment is used for relapsed or refractory HL that is CD30-positive? A. Rituximab B. Ibrutinib C. Brentuximab Vedotin D. Venetoclax

Answer 96

C. Brentuximab Vedotin Rationale: Brentuximab Vedotin (anti-CD30 monoclonal antibody) is used in relapsed HL cases.

Question 97

14. Which of the following factors is associated with a poor prognosis in Hodgkin’s lymphoma? A. Stage I or II disease B. Absence of B symptoms C. Age >45 years D. Female sex

Answer 97

C. Age >45 years Rationale: Older age (>45), male sex, B symptoms, and advanced-stage disease are poor prognostic factors.

Question 98

15. What is the most common cause of death in long-term survivors of Hodgkin’s lymphoma? A. Richter’s transformation B. Treatment-related toxicity (e.g., secondary malignancies, cardiac disease) C. Disease progression D. Opportunistic infections

Answer 98

B. Treatment-related toxicity (e.g., secondary malignancies, cardiac disease) Rationale: Long-term survivors of HL are at risk of secondary malignancies (e.g., lung or breast cancer) and cardiotoxicity from chemotherapy/radiation.

Question 99

1. Which of the following statements regarding hemophilia is true? A. Hemophilia A is due to Factor IX deficiency. B. Hemophilia B is more common than Hemophilia A. C. Hemophilia is an autosomal dominant disorder. D. Hemophilia A is the most common inherited coagulation disorder affecting males.

Answer 99

D. Hemophilia A is the most common inherited coagulation disorder affecting males. Rationale: Hemophilia A (Factor VIII deficiency) accounts for 80% of all hemophilia cases and follows an X-linked recessive inheritance, primarily affecting males.

Question 100

3. Which of the following is the most common site of spontaneous bleeding in severe hemophilia? A. Gastrointestinal tract B. Joints (hemarthrosis) C. Lungs D. Skin and mucous membranes

Answer 100

B. Joints (hemarthrosis) Rationale: Recurrent hemarthrosis (bleeding into joints) is the most common feature of severe hemophilia, particularly in the knees, elbows, and ankles.

Question 101

5. A patient with hemophilia A presents with a large, painful swelling in the iliopsoas region after mild trauma. Which of the following is the most appropriate next step? A. Perform a lumbar puncture B. Give Factor VIII replacement therapy C. Start aspirin for pain relief D. Observe and re-evaluate in 24 hours

Answer 101

B. Give Factor VIII replacement therapy Rationale: Iliopsoas hematomas can cause femoral nerve compression, leading to neurologic deficits. Prompt Factor VIII replacement is essential to prevent complications.

Question 102

6. A patient with hemophilia is suspected to have a bleeding disorder. Which coagulation test result is expected? A. Normal PT, prolonged aPTT B. Prolonged PT, normal aPTT C. Prolonged PT and aPTT D. Normal PT and aPTT

Answer 102

A. Normal PT, prolonged aPTT Rationale: Hemophilia (Factor VIII or IX deficiency) leads to a prolonged aPTT, while PT remains normal because the extrinsic pathway is unaffected.

Question 103

7. A mixing study is performed on a patient with prolonged aPTT. The test result shows correction of the aPTT after mixing normal plasma. What does this indicate? A. Factor inhibitor (e.g., acquired hemophilia) B. Factor deficiency (e.g., hemophilia A or B) C. Vitamin K deficiency D. Disseminated Intravascular Coagulation (DIC)

Answer 103

B. Factor deficiency (e.g., hemophilia A or B) Rationale: In factor deficiencies (e.g., hemophilia A/B), a mixing study corrects the aPTT, confirming the absence of an inhibitor.

Question 104

8. Which test is most specific for diagnosing hemophilia A? A. Bleeding time B. Platelet count C. Factor VIII activity level D. D-dimer test

Answer 104

C. Factor VIII activity level Rationale: Factor VIII activity measurement confirms hemophilia A, while Factor IX activity confirms hemophilia B. HEMOPHILIA A = 8 HEMOPHILIA B = 9

Question 105

1. What is the most common inherited bleeding disorder? A. Hemophilia A B. Von Willebrand Disease (VWD) C. Factor V Leiden D. Antithrombin III Deficiency

Answer 105

B. Von Willebrand Disease (VWD) Rationale: VWD is the most common inherited bleeding disorder, affecting approximately 1% of the population.

Question 106

2. What is the inheritance pattern of most cases of von Willebrand disease (VWD)? A. Autosomal recessive B. Autosomal dominant C. X-linked recessive D. X-linked dominant

Answer 106

B. Autosomal dominant Rationale: VWD is primarily autosomal dominant, affecting both genders equally. However, Type 3 VWD (severe form) follows autosomal recessive inheritance.

Question 107

3. Which type of von Willebrand disease (VWD) is the most common? A. Type 1 B. Type 2A C. Type 2B D. Type 3

Answer 107

A. Type 1 Rationale: Type 1 VWD is the most common (75% of cases) and is due to a partial quantitative deficiency of von Willebrand factor (VWF), leading to mild bleeding.

Question 108

5. Which type of von Willebrand disease is the most severe and results in a near absence of VWF? A. Type 1 B. Type 2A C. Type 2B D. Type 3

Answer 108

D. Type 3 Rationale: Type 3 VWD is rare but the most severe due to complete absence of von Willebrand factor, leading to severe bleeding similar to hemophilia.

Question 109

6. Which of the following is the most common symptom in von Willebrand disease (VWD)? A. Spontaneous joint bleeding B. Mucocutaneous bleeding (epistaxis, menorrhagia, easy bruising) C. Hemoptysis D. Deep muscle hematomas

Answer 109

B. Mucocutaneous bleeding (epistaxis, menorrhagia, easy bruising) Rationale: VWD primarily causes mucocutaneous bleeding (epistaxis, menorrhagia, easy bruising), unlike hemophilia, which presents with deep tissue bleeding (e.g., hemarthrosis).

Question 110

7. A 23-year-old woman with von Willebrand disease has heavy menstrual bleeding (menorrhagia). What is the most appropriate first-line treatment? A. Tranexamic acid B. Aspirin C. Warfarin D. Heparin

Answer 110

A. Tranexamic acid Rationale: Tranexamic acid (an antifibrinolytic) is useful for menorrhagia in VWD by stabilizing clots and reducing excessive bleeding.

Question 111

8. A patient with von Willebrand disease undergoes dental extraction and experiences prolonged bleeding. What is the best initial treatment? A. Fresh Frozen Plasma B. Desmopressin (DDAVP) C. Warfarin D. Clopidogrel

Answer 111

B. Desmopressin (DDAVP) Rationale: Desmopressin (DDAVP) increases von Willebrand factor (VWF) release from endothelial cells and is the first-line treatment for mild to moderate VWD in minor procedures.

Question 112

9. Which of the following is typically abnormal in von Willebrand disease? A. PT (Prothrombin Time) B. aPTT (Activated Partial Thromboplastin Time) C. Platelet count D. D-dimer

Answer 112

B. aPTT (Activated Partial Thromboplastin Time) Rationale: aPTT may be prolonged in VWD, especially if Factor VIII levels are low, since VWF stabilizes Factor VIII. PT remains normal.

Question 113

1. Which of the following is the most common cause of disseminated intravascular coagulation (DIC)? A. Trauma B. Malignancy C. Sepsis (Gram-negative bacteria) D. Snake bites

Answer 113

C. Sepsis (Gram-negative bacteria) Rationale: Sepsis, particularly Gram-negative bacterial infections, is the most common trigger of DIC due to endotoxin-induced activation of the coagulation cascade.

Question 114

2. A pregnant woman develops acute respiratory distress and sudden coagulopathy after delivery. Which of the following conditions is the most likely cause of DIC in this setting? A. Placenta previa B. Preeclampsia C. Amniotic fluid embolism D. Ectopic pregnancy

Answer 114

C. Amniotic fluid embolism Rationale: Obstetric causes of DIC include amniotic fluid embolism, placental abruption, and retained dead fetus syndrome.

Question 115

3. A patient with acute DIC is most likely to present with which of the following symptoms? A. Spontaneous hemarthrosis B. Isolated deep vein thrombosis (DVT) C. Widespread bleeding and organ failure D. Hemiparesis and facial droop

Answer 115

C. Widespread bleeding and organ failure Rationale: Acute DIC leads to severe bleeding (petechiae, ecchymosis, GI/CNS hemorrhage) and microvascular thrombosis, which can cause multi-organ failure.

Question 116

4. Chronic DIC is most commonly associated with which of the following conditions? A. Acute myeloid leukemia (AML) B. Malignancy (e.g., solid tumors) C. Sepsis D. Obstetric complications

Answer 116

B. Malignancy (e.g., solid tumors) Rationale: Chronic DIC is most commonly seen in malignancies, where thrombosis predominates over bleeding.

Question 117

5. Which of the following laboratory findings is most suggestive of DIC? A. Normal PT and PTT, low platelet count B. Prolonged PT and PTT, low fibrinogen, elevated D-dimer C. Increased platelet count, normal fibrinogen, normal PT and PTT D. Normal PT and PTT, normal fibrinogen, normal D-dimer

Answer 117

B. Prolonged PT and PTT, low fibrinogen, elevated D-dimer Rationale: DIC is characterized by prolonged PT and PTT, thrombocytopenia, decreased fibrinogen, and elevated D-dimer due to excessive clotting and fibrinolysis.

Question 118

6. Which of the following is considered the best marker for diagnosing DIC? A. Platelet count B. D-dimer C. Prothrombin time (PT) D. Factor VIII level

Answer 118

B. D-dimer Rationale: D-dimer is the most sensitive marker for DIC, reflecting excess fibrinolysis due to ongoing clot breakdown.

Question 119

7. A blood smear in a patient with DIC is most likely to show which of the following findings? A. Target cells B. Schistocytes (fragmented RBCs) C. Heinz bodies D. Spherocytes

Answer 119

B. Schistocytes (fragmented RBCs) Rationale: Schistocytes (helmet cells) are seen due to microangiopathic hemolytic anemia (MAHA) caused by fibrin deposition in small vessels.

Question 120

9. A patient with DIC and severe thrombocytopenia (<20,000/µL) is experiencing significant bleeding. What is the next best step? A. Platelet transfusion B. Heparin infusion C. IV antibiotics only D. Warfarin therapy

Answer 120

A. Platelet transfusion Rationale: Platelet transfusion is indicated in DIC when platelet counts are <20,000/µL with active bleeding.

Question 121

1. What is the most common acute leukemia in adults? A. Acute Myeloid Leukemia (AML) B. Acute Lymphoblastic Leukemia (ALL) C. Chronic Myeloid Leukemia (CML) D. Chronic Lymphocytic Leukemia (CLL)

Answer 121

A. Acute Myeloid Leukemia (AML) Rationale: AML is the most common acute leukemia in adults, accounting for 31% of all new acute leukemia cases.

Question 122

3. Which of the following increases the risk of developing AML? A. Clonal hematopoiesis of indeterminate potential (CHIP) B. Smoking C. Prior chemotherapy (alkylating agents, topoisomerase II inhibitors) D. All of the above

Answer 122

D. All of the above Rationale: AML risk is increased by CHIP mutations (DNMT3A, TET2, ASXL1), environmental exposures (smoking, benzene), and prior chemotherapy.

Question 123

4. Which of the following is a known cytotoxic chemotherapy agent associated with therapy-related AML? A. Methotrexate B. Alkylating agents and topoisomerase II inhibitors C. Tyrosine kinase inhibitors D. Corticosteroids

Answer 123

B. Alkylating agents and topoisomerase II inhibitors Rationale: Prior chemotherapy, particularly alkylating agents (e.g., cyclophosphamide) and topoisomerase II inhibitors (e.g., etoposide), increases the risk of therapy-related AML.

Question 124

5. Which of the following is a hallmark sign of acute myeloid leukemia (AML)? A. Pancytopenia with circulating myeloblasts B. Hypercalcemia C. Smudge cells on peripheral smear D. Lytic bone lesions

Answer 124

A. Pancytopenia with circulating myeloblasts Rationale: AML is characterized by bone marrow failure leading to anemia, thrombocytopenia, and neutropenia, often with circulating myeloblasts.

Question 125

6. Which subtype of AML is associated with gingival hyperplasia? A. Acute Promyelocytic Leukemia (APL) B. Monocytic AML C. Megakaryoblastic AML D. Therapy-related AML

Answer 125

B. Monocytic AML Rationale: Monocytic AML (M5 subtype) frequently presents with gingival hyperplasia due to tissue infiltration.

Question 126

7. What is the hallmark finding on peripheral blood smear in AML? A. Smudge cells B. Auer rods in myeloblasts C. Bite cells D. Target cells

Answer 126

B. Auer rods in myeloblasts Rationale: Auer rods (needle-like inclusions in myeloblasts) are specific for AML.

Question 127

16. What is the most common cause of death in AML? A. Cardiac arrhythmia B. Infections (bacterial, fungal sepsis) C. Pulmonary embolism D. Stroke

Answer 127

B. Infections (bacterial, fungal sepsis) Rationale: Severe neutropenia in AML leads to life-threatening infections, the most common cause of death.

Question 128

5. Which of the following is the most common physical finding in CML? A. Hepatomegaly B. Lymphadenopathy C. Splenomegaly D. Skin rash

Answer 128

C. Splenomegaly Rationale: Splenomegaly is the most common physical finding in CML and is often associated with early satiety due to splenic enlargement.

Question 129

7. A patient with suspected CML undergoes a CBC. What is the most characteristic laboratory finding? A. Pancytopenia B. Marked leukocytosis (>100,000 WBC/µL) C. Thrombocytopenia D. Increased lymphocytes

Answer 129

B. Marked leukocytosis (>100,000 WBC/µL) Rationale: CML is characterized by marked leukocytosis with left-shifted granulocytosis, including neutrophils, basophils, and eosinophils.

Question 130

8. Which of the following findings on peripheral blood smear is most suggestive of CML? A. Auer rods B. Smudge cells C. Left shift with myelocytes and metamyelocytes D. Howell-Jolly bodies

Answer 130

C. Left shift with myelocytes and metamyelocytes Rationale: CML presents with a "left shift", meaning an increased number of immature myeloid precursors, including myelocytes and metamyelocytes.

Question 131

9. What percentage of CML cases are diagnosed in the chronic phase? A. 30% B. 50% C. 90% D. 100%

Answer 131

C. 90% Rationale: Most CML cases (~90%) are diagnosed in the chronic phase, characterized by leukocytosis and splenomegaly with <10% blasts in the bone marrow.

Question 132

10. What is the defining feature of blast crisis in CML? A. Platelet count >1,000,000/µL B. Splenomegaly C. Blasts ≥20% in peripheral blood or bone marrow D. Leukocytosis >50,000 WBC/µL

Answer 132

C. Blasts ≥20% in peripheral blood or bone marrow Rationale: Blast crisis is defined as ≥20% blasts in the blood or bone marrow, resembling acute leukemia (AML or ALL).

Question 133

11. What is the first-line treatment for CML? A. Chemotherapy B. Corticosteroids C. Tyrosine kinase inhibitors (TKIs) D. Hematopoietic stem cell transplant

Answer 133

C. Tyrosine kinase inhibitors (TKIs) Rationale: TKIs, such as Imatinib, are first-line therapy for CML and target the BCR-ABL1 oncoprotein.