Hematopathology Practice Questions

Q: A 13-year-old female attends a hematology clinic for follow-up of a coagulation defect in the extrinsic pathway. Which coagulation factor is defective?

VII. **Explanation:** The coagulation cascade is traditionally divided into the intrinsic, extrinsic, and common pathways. To answer this question, one must identify which factor is unique to the **extrinsic pathway**. 1. **Why Factor VII is correct:** Factor VII is the only factor involved exclusively in the extrinsic pathway [2]. This pathway is initiated when subendothelial **Tissue Factor (Factor III)** is exposed to circulating Factor VII following vascular injury. The resulting TF-VIIa complex then activates Factor X (the start of the common pathway). In clinical practice, a defect in the extrinsic pathway is characterized by an isolated prolongation of **Prothrombin Time (PT)**, while the Activated Partial Hypotension Time (aPTT) remains normal. 2. **Why the other options are incorrect:** * **Factors VIII, IX, and XI** are all components of the **intrinsic pathway**. * Deficiencies in these factors (e.g., Hemophilia A [VIII], Hemophilia B [IX], or Hemophilia C [XI]) result in a prolonged **aPTT**, while the PT remains normal [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for PT/Extrinsic:** "PET" (PT, Extrinsic, Tissue Factor/Factor VII). * **Mnemonic for aPTT/Intrinsic:** "PITT" (PTT, Intrinsic, Twelve, Eleven, Ten, Nine, Eight—though note Factor X is common). * **Factor VII** has the **shortest half-life** (approx. 4–6 hours) among all clotting factors [1]. Therefore, PT is the first lab value to become deranged in acute liver failure or early Warfarin therapy. * **Vitamin K-dependent factors:** II, VII, IX, and X (Factor VII is the most sensitive to Vitamin K deficiency) [1]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 582-583. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, pp. 128-130.

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

Factor IX. **Explanation:** Hemophilia B, also known as **Christmas Disease**, is an X-linked recessive bleeding disorder caused by a deficiency of **Factor IX**. Factor IX is a vitamin K-dependent serine protease [1] that plays a critical role in the intrinsic pathway of the coagulation cascade by activating Factor X. **Analysis of Options:** * **Factor IX (Correct):** Deficiency leads to Hemophilia B. It is clinically indistinguishable from Hemophilia A, presenting with hemarthrosis (joint bleeding), muscle hematomas, and prolonged bleeding after trauma. * **Factor VIII (Incorrect):** Deficiency of Factor VIII causes **Hemophilia A** (Classic Hemophilia), which is the most common hereditary disease associated with life-threatening bleeding. * **Factor VII (Incorrect):** Deficiency of Factor VII affects the **extrinsic pathway** [1]. It is rare and typically presents with a prolonged Prothrombin Time (PT) but a normal Activated Partial Thromboplastin Time (aPTT). * **Factor X (Incorrect):** Factor X is the start of the **common pathway**. Deficiency is rare and affects both PT and aPTT [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Both Hemophilia A and B are **X-linked recessive** (affecting males; females are typically asymptomatic carriers). * **Lab Findings:** Characterized by **prolonged aPTT** with a **normal PT and normal bleeding time** (platelet function is unaffected). * **Mixing Study:** A 1:1 mixing study will **correct** the aPTT in Hemophilia, distinguishing it from disorders caused by coagulation inhibitors (like Lupus anticoagulant). * **Treatment:** Factor IX concentrate is the treatment of choice for Hemophilia B. Fresh Frozen Plasma (FFP) can be used if specific concentrates are unavailable. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 582-583.

Question 1

ADAMTS13 deficiency is seen in which condition?

Accepted Answer

Thrombotic thrombocytopenic purpura (TTP)

Answer

Hemolytic uremic syndrome (HUS)

Answer

Wegener's granulomatosis

Answer

Membranous nephropathy

Question 2

A 13-year-old female attends a hematology clinic for follow-up of a coagulation defect in the extrinsic pathway. Which coagulation factor is defective?

Accepted Answer

VII

Answer

VIII

Answer

IX

Answer

XI

Question 3

Multiple myeloma is diagnosed by which of the following criteria?

Accepted Answer

Greater than 10% plasmacytosis

Answer

24-hour urine protein measurement

Answer

Kidney biopsy

Answer

Rouleaux formation in peripheral blood smear

Question 4

Hemophilia B is due to deficiency of which clotting factor?

Accepted Answer

Factor IX

Answer

Factor VIII

Answer

Factor VII

Answer

Factor X

Question 5

Ham's test is used in the screening of which of the following conditions?

Accepted Answer

Paroxysmal nocturnal hemoglobinuria

Answer

Hereditary spherocytosis

Answer

G6PD deficiency

Answer

Any hemolytic disorder

Question 6

Glucose-6-phosphate dehydrogenase deficiency causes which of the following conditions?

Accepted Answer

Hemolytic anemia

Answer

Hemophilia

Answer

Aplastic anemia

Answer

Megaloblastic anemia

Question 7

Massive splenomegaly is defined if the spleen weighs greater than:

Accepted Answer

1 kg

Answer

500 grams

Answer

1.5 kg

Answer

2 kg

Question 8

Which of the following conditions is most likely to lead to a dry tap during bone marrow aspiration?

Accepted Answer

Idiopathic myelofibrosis

Answer

Acute lymphoblastic leukemia

Answer

Multiple myeloma

Answer

Megaloblastic anaemia

Question 9

Glycosylated hemoglobin (HbA2) levels are elevated in which of the following conditions?

Accepted Answer

Beta thalassemia trait

Answer

Sickle cell anemia

Answer

Hereditary spherocytosis

Answer

None of the above

Question 10

What is MCV?

Accepted Answer

Normal value is 82-92 FL

Answer

Increased in aplastic anemia

Answer

Decreased in B12 deficiency

Answer

Normal in iron deficiency anemia

Hematopathology — MCQs

Hematopathology — MCQs

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