INI-CET 2021 - Pathology PYQs Practice Questions

Q: Which of the following causes aplastic crisis in hereditary spherocytosis?

Parvovirus. ***Parvovirus*** - **Parvovirus B19** specifically targets and destroys **erythroid precursors** in the bone marrow, leading to a temporary cessation of red blood cell production [1]. - In patients with conditions like **hereditary spherocytosis** who already have chronic hemolysis and increased erythropoiesis, this interruption can cause a sudden and severe drop in hemoglobin, known as an **aplastic crisis** [1]. *Poxvirus* - Poxviruses primarily cause **skin lesions** and systemic symptoms like fever and malaise, with diseases such as smallpox or molluscum contagiosum. - They are not known to directly cause **aplastic crisis** by targeting erythroid progenitors. *Adenovirus* - Adenoviruses commonly cause **respiratory tract infections**, gastroenteritis, and conjunctivitis. - While they can cause various symptoms, they are not typically associated with **aplastic crisis** in the context of hereditary spherocytosis. *Epstein-Barr virus* - **Epstein-Barr virus (EBV)** is known to cause **infectious mononucleosis** and is associated with certain lymphomas and nasopharyngeal carcinoma. - Although it can rarely cause **hemophagocytic lymphohistiocytosis** leading to pancytopenia, it does not typically induce **aplastic crisis** in hereditary spherocytosis by directly targeting erythroid precursors. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 641-642. [Practice more Pathology PYQs on OnCourse]

Q: Which is the cell of origin of Chronic Lymphocytic Leukaemia / Small Lymphocytic Lymphoma?

Naïve B cells. ***Naïve B cells*** - Chronic Lymphocytic Leukaemia (CLL) and Small Lymphocytic Lymphoma (SLL) originate from **CD5-positive B lymphocytes** arrested in a mature but **naïve differentiation stage** [1]. - These cells express both **B-cell markers (CD19, CD20, CD23)** and a T-cell marker (CD5), which is characteristic of the clone [4]. *Mature B cells* - While CLL/SLL are derived from B cells, they are specifically from **naïve, not fully mature, B cells**. - **Other B-cell lymphomas** like follicular lymphoma or mantle cell lymphoma originate from distinct stages of mature B-cell differentiation [2]. *Progenitor T cells* - **Progenitor T cells** are the cells of origin for **T-cell acute lymphoblastic leukaemia (T-ALL)**, not CLL/SLL [3]. - T-ALL involves immature T lymphocytes and presents with different clinical and immunophenotypic features [3]. *Mature T cells* - **Mature T cells** can give rise to various **peripheral T-cell lymphomas**, like peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) or cutaneous T-cell lymphoma (Mycosis Fungoides). - These are distinct from CLL/SLL, which is a B-cell neoplasm [4]. **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. 596-598. [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. 610-612. [3] 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. 598-599. [4] 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. 598. [Practice more Pathology PYQs on OnCourse]

Q: Arrange the following cellular events of inflammation in the correct sequence: 1. Rolling 2. Cytokine-mediated integrin activation 3. Adhesion 4. Migration

1,2,3,4. ***1,2,3,4*** - The correct sequence of cellular events for leukocyte recruitment during inflammation begins with **rolling** [1], followed by **cytokine-mediated integrin activation** [2], then firm **adhesion** to the endothelium [1], and finally **migration** (diapedesis) into the tissues [3]. - This step-by-step process ensures effective targeting of leukocytes to the site of injury or infection [1]. *3,4,1,2* - This sequence is incorrect as **adhesion** cannot occur before **rolling**, and **migration** is the final step after adhesion, not an early one. - **Cytokine-mediated integrin activation** must precede firm adhesion [1]. *2,1,4,3* - This order is incorrect because **rolling** (1) is the initial interaction that allows leukocytes to slow down on the endothelium [2], and it occurs before **cytokine-mediated integrin activation** (2) which strengthens the binding. - **Migration** (4) is also misplaced as it should be the last step after firm adhesion (3). *4,1,2,3* - This sequence is incorrect as **migration** (4) is the last step in the process, not the first. - **Rolling** (1) initiates the process by transiently interacting with endothelial cells, followed by activation and adhesion. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 87. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Migration in the tissues toward a chemotactic stimulus, pp. 86-87. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 87-89. [Practice more Pathology PYQs on OnCourse]

Question 1

Which of the following causes aplastic crisis in hereditary spherocytosis?

Accepted Answer

Parvovirus

Answer

Poxvirus

Answer

Adenovirus

Answer

Epstein-Barr virus

Question 2

Which cell acts as the primary effector cell in type IV (delayed-type) hypersensitivity reactions?

Accepted Answer

Macrophage

Answer

Neutrophil

Answer

Dendritic cell

Answer

Cytotoxic T cell

Question 3

Which is the cell of origin of Chronic Lymphocytic Leukaemia / Small Lymphocytic Lymphoma?

Accepted Answer

Naïve B cells

Answer

Mature B cells

Answer

Progenitor T cells

Answer

Mature T cells

Question 4

Arrange the following cellular events of inflammation in the correct sequence:

1. Rolling
2. Cytokine-mediated integrin activation
3. Adhesion
4. Migration

Accepted Answer

1,2,3,4

Answer

3,4,1,2

Answer

2,1,4,3

Answer

4,1,2,3

Question 5

A 5 year old child who presented with proptosis of one of the eyes was found to have a desmin positive tumour. What is the probable diagnosis?

Accepted Answer

Rhabdomyosarcoma

Answer

Neuroblastoma

Answer

Retinoblastoma

Answer

Ewing's sarcoma

Question 6

Which of the following is true?

1. BRCA1 is an oncogene
2. HER2neu is amplified only in a fraction of breast cancer
3. EGFR (+) is seen in non-small cell lung cancer
4. N-MYC is a tumor suppressor gene

Accepted Answer

2,3

Answer

1,3

Answer

1,2

Answer

All of the options

Question 7

A patient with lytic lesions on the skull is suspected of a diagnosis of Langerhans cell histiocytosis. Which of the following is a characteristic finding on electron microscopy?

Accepted Answer

Birbeck granules

Answer

Eosinophils

Answer

Histiocytes

Answer

Giant cells

Question 8

A person was brought to the emergency department with facial swelling, itching, and hypotension following a bee sting. The mentioned clinical features are due to the increase in which immunoglobulin?

Accepted Answer

IgE

Answer

IgG

Answer

IgA

Answer

IgM

Question 9

A 42 year-old female patient presents with cough, low-grade fever, and hemoptysis.
Investigations reveal a cavitary lesion on her right lung apex, which on biopsy reveals caseous necrosis. The underlying pathophysiology is:

Accepted Answer

Type 4 hypersensitivity reaction

Answer

Sudden cut off of blood supply

Answer

Enzyme degradation

Answer

Fibrinoid deposition

Question 10

A boy presents with fever, night sweats, and neck swelling. The biopsy of swelling showed a starry sky appearance. What is the most likely genetic abnormality seen in this case?

Accepted Answer

MYC

Answer

RAS

Answer

BCR-ABL

Answer

p53

INI-CET 2021 — Pathology