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 karyotyping image is given below. What are the clinical features most likely to be expected in such patients?

Accepted Answer

Gynecomastia and long limbs

Answer

Flat occiput

Answer

Webbed neck and shield chest

Answer

Epicanthal folds and single palmar crease

Question 8

Which of the following can be prevented by transfusing irradiated RBCs?

Accepted Answer

Graft versus host disease

Answer

HLA Alloimmunization

Answer

Transfusion Related Acute Lung Injury (TRALI)

Answer

Immunomodulation

Question 9

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 10

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

INI-CET 2021 — Pathology