Hematopathology Practice Questions

Q: A 3-year-old female child presented with skin papules. Which of the following is a marker of Langerhans cell histiocytosis?

CD 1a. **Explanation:** Langerhans Cell Histiocytosis (LCH) is a clonal proliferation of Langerhans cells, which are specialized dendritic cells [1]. In children, it often presents with seborrheic-like skin rashes (papules), lytic bone lesions, or multi-organ involvement. **Why CD1a is correct:** Langerhans cells are characterized by the expression of specific surface markers and the presence of Birbeck granules (tennis-racket shaped organelles) on electron microscopy [1]. **CD1a** and **Langerin (CD207)** are the most specific immunohistochemical markers used to confirm a diagnosis of LCH. CD1a is a major histocompatibility complex (MHC) class I-like molecule involved in lipid antigen presentation. **Analysis of Incorrect Options:** * **CD3:** This is a definitive marker for **T-lymphocytes**. While T-cells may be present in the inflammatory background of LCH lesions, they are not the neoplastic cells. * **CD68:** This is a marker for **macrophages/monocytes**. While LCH cells may show weak positivity for CD68, it is non-specific and found in various other histiocytic disorders (like Sinus Histiocytosis). * **CD57:** This is a marker for **Natural Killer (NK) cells** and certain neuroendocrine tissues; it has no diagnostic role in LCH. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Marker:** Langerin (CD207) is more specific than CD1a because it correlates directly with the presence of Birbeck granules [1]. * **S100:** LCH cells are also characteristically **S100 positive** (though non-specific). * **Electron Microscopy:** Look for **Birbeck Granules** (pentalaminar, rod-shaped structures with a bulbous end) [1]. * **Genetics:** Over 50% of LCH cases harbor the **BRAF V600E mutation**, which is a frequent target in recent exam questions [1]. **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. 629-630.

Q: What is true about iron deficiency anemia?

Anisocytosis. In Iron Deficiency Anemia (IDA), the hallmark finding on a peripheral blood smear is a **microcytic hypochromic** picture [1]. **Why Anisocytosis is Correct:** Anisocytosis refers to a variation in the size of Red Blood Cells (RBCs). In the early stages of IDA, the bone marrow produces smaller (microcytic) cells alongside existing normal-sized (normocytic) cells [1]. This variation is quantitatively reflected as an **increased Red Cell Distribution Width (RDW)**. An increased RDW is one of the earliest and most sensitive indicators of IDA, helping to differentiate it from Beta-Thalassemia trait (where RDW is typically normal). **Why Other Options are Incorrect:** * **Howell-Jolly Bodies:** These are nuclear remnants (DNA) seen in RBCs. They are characteristic of **asplenia** (post-splenectomy) or functional hyposplenism (e.g., Sickle Cell Anemia), not IDA. * **Polychromasia:** This represents young, bluish-grey RBCs (reticulocytes) on a Giemsa stain. Polychromasia indicates active erythropoiesis, typically seen in **hemolytic anemias** or after acute blood loss. In IDA, there is a lack of iron to produce new cells, leading to a low reticulocyte count (hypoproliferative state) [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Morphology:** IDA shows microcytic hypochromic cells, **pencil cells** (elliptocytes), and occasionally target cells [1]. * **Best Screening Test:** Serum Ferritin (decreased). It is the first parameter to decrease in iron deficiency. * **Mentzer Index:** MCV/RBC count. If >13, it suggests IDA; if <13, it suggests Thalassemia trait. * **Gold Standard:** Bone marrow aspiration with **Prussian Blue staining** (Perl’s stain) showing absent hemosiderin in macrophages. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 589-591.

Q: Which CD marker is characteristic of histiocytosis?

CD1a. **Explanation:** **Langerhans Cell Histiocytosis (LCH)** is a proliferative disorder of Langerhans cells, which are specialized dendritic cells [1]. The diagnosis relies on identifying specific immunophenotypic markers and ultrastructural features. **Why CD1a is the correct answer:** CD1a is a non-classical MHC class I-like molecule involved in presenting lipid antigens to T-cells. It is the **most specific and characteristic surface marker** used in immunohistochemistry to identify Langerhans cells. In the context of LCH, cells typically express **CD1a, CD207 (Langerin), and S-100**. Among these, CD207 is the most specific as it correlates with the presence of Birbeck granules. **Why the other options are incorrect:** * **CD1b, CD1c, and CD1d:** While these are also members of the CD1 family involved in lipid antigen presentation, they are expressed on different subsets of dendritic cells, B-cells, or cortical thymocytes. They are not used as diagnostic markers for LCH in clinical pathology. Specifically, CD1d is known for presenting glycolipids to Natural Killer T (NKT) cells. **High-Yield Clinical Pearls for NEET-PG:** * **Electron Microscopy:** The pathognomonic finding in LCH is the **Birbeck Granule**, which has a characteristic "tennis-racket" appearance [1]. * **Langerin (CD207):** This is the protein constituent of Birbeck granules and is considered the most specific marker for LCH [1]. * **Clinical Triad (Hand-Schüller-Christian disease):** Calvarial bone defects, exophthalmos, and diabetes insipidus. * **Letterer-Siwe Disease:** The aggressive, multisystem form seen in infants (<2 years) involving skin rash, hepatosplenomegaly, and bone lesions. **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. 629-630.

Q: All of the following statements about Hairy cell leukaemia are true except?

Results from an expansion of neoplastic T lymphocytes. **Explanation:** **Hairy Cell Leukemia (HCL)** is a rare, chronic B-cell lymphoproliferative disorder. The correct answer is **B** because HCL is a neoplasm of **mature B-lymphocytes**, not T-lymphocytes [1]. 1. **Why Option B is the answer:** The "hairy cells" are derived from post-germinal center memory B-cells. They typically express pan-B-cell markers (CD19, CD20, CD22) and specific markers like CD11c, CD25, CD103, and Annexin A1. 2. **Why Option A is incorrect:** Splenomegaly is a hallmark of HCL and is often "conspicuous" or massive [1]. It occurs due to the infiltration of the red pulp by leukemic cells, leading to a "beefy red" appearance of the spleen [1]. Notably, lymphadenopathy is usually absent. 3. **Why Option C is incorrect:** Historically, the **TRAP (Tartrate-Resistant Acid Phosphatase)** stain was the gold standard for diagnosis. Hairy cells contain an isoenzyme of acid phosphatase that is not inhibited by tartrate. 4. **Why Option D is incorrect:** CD25 (the IL-2 receptor alpha chain) is a highly consistent and sensitive marker for HCL, used in flow cytometry to differentiate it from other B-cell lymphomas. **High-Yield Clinical Pearls for NEET-PG:** * **BRAF V600E Mutation:** Present in nearly 100% of classic HCL cases (Diagnostic). * **Dry Tap:** Bone marrow aspiration often results in a "dry tap" due to extensive **reticulin fibrosis** induced by the tumor cells [1]. * **Fried Egg Appearance:** Seen on bone marrow biopsy (cells have abundant cytoplasm and distinct borders). * **Monocytopenia:** A characteristic hematological finding. * **Treatment:** Highly sensitive to Purine analogs like **Cladribine** (2-CdA). **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. 612.

Question 1

A 3-year-old female child presented with skin papules. Which of the following is a marker of Langerhans cell histiocytosis?

Accepted Answer

CD 1a

Answer

CD 3

Answer

CD 68

Answer

CD 57

Question 2

What is true about iron deficiency anemia?

Accepted Answer

Anisocytosis

Answer

Howel Jolly bodies

Answer

Polychromasia

Answer

All of the above

Question 3

What is the most common leukemia seen in individuals with Down syndrome?

Accepted Answer

Acute Lymphoblastic Leukemia (ALL)

Answer

Acute Myeloid Leukemia (AML)

Answer

Chronic Lymphocytic Leukemia (CLL)

Answer

Chronic Myeloid Leukemia (CML)

Question 4

Which of the following is true about acute myelogenous leukemia?

Accepted Answer

Auer bodies are seen

Answer

Philadelphia chromosome is seen

Answer

Common in childhood

Answer

Peroxidase negative granules

Question 5

A 25-year-old female presented with painless cervical lymphadenopathy for 2 months. On examination, the lymph nodes were firm in consistency. Epitrochlear lymph nodes were also involved. There was also a history of fever, night sweats, and significant weight loss. A lymph node biopsy was conducted for histopathological examination and flow cytometry studies. Which of the following genes is involved in this condition?

Accepted Answer

Bcl-2

Answer

Bcl-1

Answer

Bcl-6

Answer

Bcl-4

Question 6

Which of the following conditions is characterized by increased PT and normal PTT?

Accepted Answer

Factor 7 deficiency

Answer

Von Willebrand's disease

Answer

Factor 8 deficiency

Answer

Thrombin deficiency

Question 7

Coagulation defect involving both the arterial and venous system is seen in which of the following conditions?

Accepted Answer

Hyperhomocystinemia

Answer

Factor V Leiden

Answer

Protein C deficiency

Answer

Antithrombin III deficiency

Question 8

Direct Coombs test is positive in hemolytic anemia due to which of the following conditions?

Accepted Answer

Paroxysmal cold hemoglobinuria

Answer

Paroxysmal nocturnal hemoglobinuria

Answer

Hereditary spherocytosis

Answer

Idiopathic thrombocytopenic purpura

Question 9

Which CD marker is characteristic of histiocytosis?

Accepted Answer

CD1a

Answer

CD1b

Answer

CD1c

Answer

CD1d

Question 10

All of the following statements about Hairy cell leukaemia are true except?

Accepted Answer

Results from an expansion of neoplastic T lymphocytes

Answer

Splenomegaly is conspicuous

Answer

Cells are positive for Tartarate Resistant Acid phosphatase

Answer

The cells express CD25 consistently

Hematopathology — MCQs

Hematopathology — MCQs

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