INI-CET 2025 - Pathology PYQs Practice Questions

Q: Which of the following is an incorrect gene-disease association?

TP53 - Mucosal Neuroma. ***TP53 - Mucosal Neuroma*** - This is an **incorrect association**. Mucosal neuromas are a hallmark feature of **Multiple Endocrine Neoplasia type 2B (MEN 2B)** [2]. - MEN 2B is caused by a germline gain-of-function mutation in the **RET proto-oncogene**, not the TP53 tumor suppressor gene (which is associated with **Li-Fraumeni syndrome**). *STK11 - Breast Cancer* - This is a **correct association**. Mutations in the **STK11** gene cause **Peutz-Jeghers syndrome (PJS)**. - Patients with PJS have a significantly increased risk of developing several malignancies, including gastrointestinal cancers and non-GI cancers like **breast cancer**. *PTEN - Thyroid Carcinoma* - This is a **correct association**. Germline mutations in the **PTEN** gene are responsible for **Cowden Syndrome**. - Cowden Syndrome is characterized by hamartomas and a high lifetime risk of developing cancers, most notably **follicular thyroid carcinoma** and breast cancer. *BRCA2 - Prostate Carcinoma* - This is a **correct association**. Germline mutations in **BRCA2** are strongly linked to hereditary breast and ovarian cancer syndromes [1]. - Men with **BRCA2** mutations have a substantially elevated risk of developing **prostate carcinoma**, often presenting with high-grade, aggressive disease. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Pancreas, pp. 898-899. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1139-1140. [Practice more Pathology PYQs on OnCourse]

Q: HLA-mismatched transplant is not a problem in which of the following diseases?

Bare lymphocyte syndrome. **Bare lymphocyte syndrome (Correct)** - **Bare Lymphocyte Syndrome** (BLS) is characterized by a failure to express **MHC Class I (Type I)** or **MHC Class II (Type II)** molecules on the cell surface, crucial for antigen presentation. - The absence of functional MHC in the recipient means their cells cannot effectively present the donor's HLA antigens, minimizing host immune rejection (host-versus-graft rejection) and allowing for the successful use of **HLA-mismatched transplants**. *Wiskott-Aldrich syndrome (Incorrect)* - This X-linked immunodeficiency involves the **WASp gene** and affects the cytoskeleton of hematopoietic cells, leading to defects in **T-cell function** and a high risk of autoimmune disease. - Since the patient's capacity for MHC presentation is generally intact, standard severe **Graft-versus-Host Disease (GvHD)** is a major risk following mismatched transplant, necessitating stringent HLA matching. *Job's syndrome (Incorrect)* - Job's syndrome (Hyper-IgE syndrome) is typically caused by mutations in **STAT3**, impairing signal transduction necessary for Th17 cell differentiation and resulting in defective neutrophil chemotaxis. - This syndrome does not eliminate the ability of the recipient's cells to express and utilize MHC molecules; therefore, an **HLA-matched donor** is required to prevent transplant rejection and GvHD. *Chediak-Higashi syndrome (Incorrect)* - Caused by a mutation in the **LYST gene**, leading to defective lysosomal trafficking, which primarily affects phagocytes and pigment cells. - Although it is an immunodeficiency, the fundamental mechanisms for T-cell recognition of foreign alloantigens (such as mismatched HLA) are functional, making a severe **HLA mismatch** highly problematic and usually fatal. [Practice more Pathology PYQs on OnCourse]

Q: In renal transplant biopsy, which of the following stains is not used to identify organisms?

Congo red. ***Congo red*** - **Congo red** is a special stain primarily used to look for **amyloid deposition**, which appears as an apple-green birefringence under polarized light [1]. - It is a diagnostic stain for **amyloidosis** and has **no role in the identification of infectious organisms** (bacteria, fungi, or parasites) in tissue biopsies [2]. - This is the stain that is **NOT used to identify organisms** in renal transplant biopsies. *Gomori methenamine silver* - This stain, often abbreviated as **GMS**, is excellent for demonstrating the cell walls of **fungi** (e.g., *Pneumocystis*, *Aspergillus*, *Cryptococcus*) which appear as black structures. - It is frequently used in transplant pathology to rule out opportunistic fungal infections. *PAS (Periodic acid-Schiff) stain* - **PAS** stain is used to highlight mucopolysaccharides, basement membranes, and certain cell walls, making it useful for identifying various organisms. - It stains the cell walls of **fungi** and the capsules of some organisms, making it valuable in detecting infections. *Masson Fontana* - **Masson Fontana** stain is primarily used to identify **melanin** pigment in tissues. - While it is not a standard organism identification stain in routine renal transplant pathology, specialized silver-based modifications have been described for detecting certain fungal organisms in research settings. - However, it is not considered a primary stain for organism identification in clinical practice. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 268-269. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 533-534. [Practice more Pathology PYQs on OnCourse]

Question 1

Which of the following is an incorrect gene-disease association?

Accepted Answer

TP53 - Mucosal Neuroma

Answer

BRCA2 - Prostate Carcinoma

Answer

STK11 - Breast Cancer

Answer

PTEN - Thyroid Carcinoma

Question 2

Which of the following is not an aneuploidy?

Accepted Answer

Bloom Syndrome

Answer

Trisomy 13

Answer

Trisomy 21

Answer

Klinefelter Syndrome

Question 3

HLA-mismatched transplant is not a problem in which of the following diseases?

Accepted Answer

Bare lymphocyte syndrome

Answer

Job's syndrome

Answer

Wiskott-Aldrich syndrome

Answer

Chediak-Higashi syndrome

Question 4

Transplant rejection does not occur in which of the following conditions?

Accepted Answer

Severe Combined Immunodeficiency (SCID)

Answer

Bare lymphocyte syndrome

Answer

Chronic granulomatous disease

Answer

DiGeorge syndrome

Question 5

In renal transplant biopsy, which of the following stains is not used to identify organisms?

Accepted Answer

Congo red

Answer

Masson Fontana

Answer

PAS (Periodic acid-Schiff) stain

Answer

Gomori methenamine silver

Question 6

Histopathological features of granulosa cell tumor include all except:

Accepted Answer

CA-125 positivity

Answer

Microfollicular pattern

Answer

Coffee bean nuclei

Answer

Call-Exner bodies

Question 7

Caspase-1 mediated cell death with inflammation is known as

Accepted Answer

Pyroptosis

Answer

Necroptosis

Answer

Necrosis

Answer

Ferroptosis

Question 8

Least common finding in diabetic kidney is

Accepted Answer

Armanni-Ebstein

Answer

Podocyte loss

Answer

GBM thickening

Answer

Mesangial widening

INI-CET 2025 — Pathology