General Pathology — MCQs

General Pathology Indian Medical PG Practice Questions and MCQs

Question 1111: What is the most common fixative used in pathology?

A. Gluteraldehyde
B. Alcohol
C. Formaldehyde (Correct Answer)
D. Picric acid

Explanation: **Explanation:** **Formaldehyde (Option C)** is the most commonly used fixative in histopathology. It is typically used as **10% Neutral Buffered Formalin (NBF)**. It works by creating cross-links between proteins (specifically forming methylene bridges), which preserves the tissue architecture and prevents autolysis and putrefaction. Its popularity stems from its low cost, ease of preparation, and the fact that it allows for a wide range of subsequent staining techniques, including H&E and Immunohistochemistry (IHC). **Analysis of Incorrect Options:** * **Glutaraldehyde (Option A):** This is the fixative of choice for **Electron Microscopy**. It provides superior preservation of ultrastructural details but penetrates tissue very slowly and makes it too brittle for routine light microscopy. * **Alcohol (Option B):** Ethanol or methanol are "dehydrating" fixatives. They are primarily used for **cytological smears** (e.g., Pap smears) because they preserve nuclear detail well, but they cause significant tissue shrinkage. * **Picric acid (Option D):** Found in **Bouin’s fluid**, it is excellent for preserving glycogen and delicate morphology (like testicular or intestinal biopsies) but can cause significant tissue hardening and yellow discoloration. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Formaldehyde acts by **cross-linking of proteins**. * **Concentration:** 10% Formalin is actually a 4% solution of formaldehyde gas in water. * **Best for EM:** Glutaraldehyde. * **Best for Lipids:** Frozen section (Formalin dissolves lipids during processing). * **Best for Enzyme Histochemistry:** Cold acetone or frozen sections. * **Carnoy’s Fluid:** A rapid fixative used for urgent biopsies and preserving nucleic acids.

Question 1112: Which of the following cytoplasmic structures contains fragmented mitochondria?

A. Pinocytotic vacuoles
B. Primary lysosomes
C. Heterophagosomes
D. Autophagosomes (Correct Answer)

Explanation: **Explanation:** The correct answer is **D. Autophagosomes**. **1. Why Autophagosomes are correct:** Autophagy ("self-eating") is a survival mechanism where a cell digests its own damaged organelles or proteins [1]. During this process, a membrane (phagophore) derived from the Endoplasmic Reticulum encircles intracellular components, such as **fragmented mitochondria** or ribosomes, to form a double-membrane-bound vesicle called an **autophagosome** [1]. This then fuses with a lysosome to form an autophagolysosome, where acid hydrolases degrade the contents. This is a hallmark of cellular adaptation to nutrient deprivation and cellular aging. **2. Why the other options are incorrect:** * **A. Pinocytotic vacuoles:** These are small vesicles formed during "cell drinking" (pinocytosis), where the cell engulfs extracellular fluid and solutes. They do not contain internal organelles like mitochondria. * **B. Primary lysosomes:** These are membrane-bound organelles containing digestive enzymes that have not yet engaged in digestive activity. They do not contain cellular debris or organelles until they fuse with a phagosome. * **C. Heterophagosomes:** These are formed during heterophagy, where the cell ingests **extracellular** material (e.g., bacteria or foreign debris) via endocytosis. They do not typically contain the cell's own mitochondria. **High-Yield NEET-PG Pearls:** * **Mitophagy:** The specific term for the selective autophagy of mitochondria [2]. * **Marker of Autophagy:** **LC3** (Microtubule-associated protein 1 light chain 3) is a commonly used protein marker for autophagosomes. * **Residual Bodies:** If the material within a phagolysosome cannot be fully digested, it persists as a residual body (e.g., **Lipofuscin** "wear-and-tear" pigment). * **Clinical Link:** Mutations in autophagy genes are linked to neurodegenerative diseases like Parkinson’s and Alzheimer’s. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, pp. 71-73. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. With Illustrations By, pp. 18-19.

Question 1113: Alpha fetoprotein is genetically and structurally related to which of the following proteins?

A. Albumin (Correct Answer)
B. Transferrin
C. Fibrinogen
D. Growth hormone

Explanation: **Explanation:** **Alpha-fetoprotein (AFP)** is a major plasma protein produced during fetal development by the yolk sac and the fetal liver. It is genetically and structurally related to **Albumin**. Both proteins belong to the same multigene family (the albumin gene family), which also includes vitamin D-binding protein and afamin. The genes for AFP and Albumin are located in tandem on **chromosome 4 (4q11-q13)**. They share significant amino acid sequence homology and structural similarities, such as a triple-domain structure. Functionally, AFP serves as the fetal counterpart to albumin, acting as the primary osmotic pressure regulator and transport protein in the fetus [2]. After birth, AFP levels decline rapidly, and albumin becomes the dominant plasma protein. **Analysis of Incorrect Options:** * **B. Transferrin:** While it is a plasma transport protein (for iron), it belongs to a different genetic family and is located on chromosome 3 [1]. * **C. Fibrinogen:** This is a large, complex glycoprotein involved in blood clotting; it lacks structural homology with the albumin family. * **D. Growth Hormone:** This is a peptide hormone produced by the anterior pituitary with a completely different molecular structure and genetic origin. **High-Yield Clinical Pearls for NEET-PG:** * **AFP as a Tumor Marker:** Elevated in **Hepatocellular Carcinoma (HCC)** and **Non-seminomatous germ cell tumors (NSGCT)**, specifically Yolk Sac Tumors. * **Maternal Serum AFP (MSAFP):** * **Increased in:** Neural tube defects (e.g., spina bifida, anencephaly), abdominal wall defects (omphalocele), and multiple pregnancies. * **Decreased in:** Down Syndrome (Trisomy 21). * **Normal Range:** In adults, AFP levels are typically <10–15 ng/mL. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 657-658. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 905-907.

Question 1114: Chronic urethral obstruction due to benign prostatic hyperplasia can lead to which of the following changes in the kidney parenchyma?

A. Hyperplasia
B. Hypertrophy
C. Atrophy (Correct Answer)
D. Dysplasia

Explanation: **Explanation:** The correct answer is **Atrophy**. **Why Atrophy is correct:** Chronic urethral obstruction caused by Benign Prostatic Hyperplasia (BPH) leads to a retrograde increase in hydrostatic pressure. This pressure is transmitted from the bladder through the ureters (hydroureter) to the renal pelvis and calyces (**hydronephrosis**) [1]. The persistent mechanical pressure on the renal parenchyma, combined with compromised local blood flow (ischemia), results in the loss of nephrons and thinning of the renal cortex and medulla [2]. This process is a classic example of **pathological pressure atrophy** [1]. **Why the other options are incorrect:** * **Hyperplasia:** This involves an increase in the number of cells. While the prostate undergoes hyperplasia in BPH, the kidney does not respond to chronic obstruction by increasing cell numbers. * **Hypertrophy:** This is an increase in the size of individual cells. While the *bladder wall* undergoes compensatory hypertrophy to pump urine past the obstruction [3], the kidney parenchyma undergoes destruction and shrinkage rather than growth. * **Dysplasia:** This refers to disordered growth and maturation of an epithelium (often pre-neoplastic) or abnormal fetal development (e.g., Multicystic Dysplastic Kidney). It is not a response to mechanical obstruction in an adult kidney. **High-Yield Clinical Pearls for NEET-PG:** * **Pressure Atrophy:** Common examples include a growing tumor causing atrophy of surrounding tissue or a stone in a gland duct causing atrophy of the gland. * **Hydronephrosis:** If unilateral, it is often due to a ureteric stone; if bilateral, it is usually due to a lower urinary tract obstruction like BPH or Posterior Urethral Valves (PUV) [1]. * **Compensatory Hypertrophy:** If one kidney is removed or fails, the *contralateral* (opposite) kidney undergoes compensatory hypertrophy to maintain renal function. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 955-957. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, pp. 47-49. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 963-964.

Question 1115: Which of the following conditions is due to a defect in the normal keratinization of the oral mucosa?

A. White sponge nevus (Correct Answer)
B. Erythema multiforme
C. Incontinentia pigmenti
D. Systemic sclerosis

Explanation: **Explanation:** **White Sponge Nevus (WSN)** is the correct answer because it is a rare, autosomal dominant hereditary condition caused by mutations in the genes encoding **Keratin 4 and Keratin 13**. These keratins are specifically expressed in the suprabasal layers of non-keratinized stratified squamous epithelium (like the oral mucosa). The mutation leads to a defect in the normal keratinization process, resulting in thick, bilateral, white, "spongy" plaques on the buccal mucosa. Histologically, it is characterized by significant **parakeratosis and intracellular edema** (clear cell change) of the spinous layer. **Analysis of Incorrect Options:** * **Erythema Multiforme:** This is an acute, self-limiting **Type IV hypersensitivity reaction** (often triggered by HSV or drugs). It involves subepithelial or intraepithelial vesiculation and "target lesions," not a primary keratinization defect. * **Incontinentia Pigmenti:** This is an X-linked dominant disorder affecting the skin, teeth, and CNS. It is characterized by a defect in the **IKBKG gene**, leading to melanin incontinence (pigment falling into the dermis), not a primary oral keratinization defect. * **Systemic Sclerosis:** This is an autoimmune connective tissue disorder characterized by **excessive collagen deposition** and fibrosis of the skin and internal organs. Oral manifestations include microstomia and widening of the PDL space, but the underlying pathology is fibrotic, not a keratin defect. **High-Yield Clinical Pearls for NEET-PG:** * **Gene Mutation:** KRT4 and KRT13 (highly specific for WSN). * **Clinical Presentation:** Asymptomatic, white, folded/velvety patches that appear in early childhood and do not disappear when stretched (unlike Leukoedema). * **Differential Diagnosis:** Must be distinguished from **Leukoplakia** (premalignant) and **Candidiasis** (scrapable). WSN is entirely benign and requires no treatment.

Question 1116: Which of the following is NOT a chemokine?

A. IL-8
B. IL-1
C. Histamine (Correct Answer)
D. Eotaxin

Explanation: **Explanation:** The core concept of this question lies in distinguishing between **chemokines** (chemotactic cytokines) and other **inflammatory mediators**. Chemokines are a specific family of small proteins (8–10 kDa) that act primarily as chemoattractants for specific types of leukocytes [3]. **Why Histamine is the Correct Answer:** Histamine is a **vasoactive amine** stored in mast cell granules [1]. Its primary functions are vasodilation and increasing vascular permeability (forming endothelial gaps) [1]. While it is a potent mediator of the immediate inflammatory response, it is **not** a protein-based chemokine [2]. It does not belong to the CC, CXC, C, or CX3C families of chemokines. **Analysis of Incorrect Options:** * **IL-8 (CXCL8):** This is the "prototypical" chemokine. It belongs to the CXC family and is the most potent chemoattractant for **neutrophils**. * **IL-1:** While primarily a pro-inflammatory cytokine (inducing fever and acute-phase reactants), certain isoforms and its role in inducing other chemokines often lead to its classification in broader inflammatory discussions [3]. However, in many classifications, IL-1 is considered a primary cytokine, but **Eotaxin** and **IL-8** are definitive chemokines. *Note: If comparing IL-1 and Histamine, Histamine is definitively a non-cytokine/non-chemokine.* * **Eotaxin (CCL11):** This belongs to the CC family and is highly specific for the recruitment of **eosinophils**, particularly in allergic inflammation and parasitic infections [3]. **High-Yield NEET-PG Pearls:** 1. **CXC Chemokines (Alpha):** Act mainly on neutrophils (e.g., IL-8). 2. **CC Chemokines (Beta):** Act on monocytes, lymphocytes, and eosinophils (e.g., MCP-1, Eotaxin, RANTES). 3. **C Chemokines (Gamma):** Specific for lymphocytes (e.g., Lymphotactin). 4. **CX3C Chemokines:** e.g., Fractalkine (exists in both membrane-bound and soluble forms). 5. **Major Chemotactic Agents (The "Big Four"):** IL-8, C5a, LTB4, and Bacterial products (N-formyl methionine). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 101. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 93-94. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 211-212.

Question 1117: Chromosomal studies are best done during which stage of the cell cycle?

A. Prophase
B. Metaphase (Correct Answer)
C. Telophase
D. Anaphase

Explanation: Chromosomal studies (Karyotyping) are best performed during the **Metaphase** of the cell cycle [1][2]. **1. Why Metaphase is the Correct Answer:** During metaphase, chromosomes reach their **maximum state of condensation**. They are highly coiled and thick, making them clearly visible under a light microscope [2]. Furthermore, the nuclear envelope has completely disappeared, and chromosomes align at the equatorial plate (metaphase plate). This distinct separation and high density allow for the most accurate identification of chromosome number and structure (e.g., detecting translocations, deletions, or trisomies) [1]. **2. Analysis of Incorrect Options:** * **Prophase:** Chromatin just begins to condense into chromosomes. They are long, thin, and entangled, making it difficult to distinguish individual pairs. * **Anaphase:** Sister chromatids begin to pull apart toward opposite poles. This movement and fragmentation make it impossible to get a clear "snapshot" of the full diploid set. * **Telophase:** Chromosomes begin to de-condense back into chromatin as the nuclear envelope reforms, losing the distinct morphology required for staining and analysis. **3. NEET-PG High-Yield Pearls:** * **Colchicine/Colcemid:** In cytogenetic labs, these drugs are used to arrest cells in metaphase by inhibiting spindle fiber formation (microtubule polymerization) [1]. * **Best Sample:** Peripheral blood T-lymphocytes (stimulated by **Phytohemagglutinin**) are the most common source for karyotyping. * **G-Banding:** Giemsa stain is the most common technique used to produce light and dark bands on metaphase chromosomes for detailed analysis [1][2]. * **Prometaphase:** While metaphase is the standard answer, "High-resolution banding" is technically done during **pro-metaphase** when chromosomes are slightly less condensed, allowing for the visualization of more bands [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 54-55. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 167-168.

Question 1118: Platelet dense granules contain all except?

A. ADP
B. 5-HT
C. Calcium
D. vWF (Correct Answer)

Explanation: **Explanation:** Platelets contain two main types of storage granules: **Alpha granules** and **Dense (Delta) granules**. Understanding the distinction between their contents is a high-yield topic for NEET-PG. **1. Why vWF is the correct answer:** **von Willebrand Factor (vWF)** is stored in **Alpha granules**, not dense granules [1]. Alpha granules are the most numerous and contain larger proteins involved in adhesion, coagulation, and repair, such as Fibrinogen, Factor V, Platelet Factor 4 (PF4), and Platelet-derived growth factor (PDGF) [2]. vWF is also synthesized and stored in the Weibel-Palade bodies of endothelial cells [1]. **2. Why the other options are incorrect:** Dense granules (Delta granules) are smaller and contain non-protein "small molecules" that facilitate platelet activation and vasoconstriction. These include: * **ADP/ATP (Option A):** Adenosine diphosphate is crucial for recruiting more platelets to the site of injury [3]. * **5-HT (Option B):** Serotonin is taken up from the plasma and stored here; it acts as a potent vasoconstrictor [4]. * **Calcium (Option C):** Ionized calcium is essential for the coagulation cascade and platelet activation. * *Note: Magnesium and Histamine are also found in dense granules.* **3. Clinical Pearls for NEET-PG:** * **Mnemonic for Dense Granules:** Remember **"SAC"** (Serotonin, ADP/ATP, Calcium). * **Storage Pool Deficiency:** A group of disorders where these granules are absent. * **Chediak-Higashi Syndrome:** Characterized by a deficiency in dense granules, leading to bleeding tendencies alongside albinism and immunodeficiency. * **Hermansky-Pudlak Syndrome:** A classic board-exam association with dense granule deficiency and oculocutaneous albinism. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 669-670. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 581-582. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, p. 128. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 94-95.

Question 1119: What is the characteristic appearance of a 'lardaceous spleen'?

A. Chronic Myeloid Leukemia (CML)
B. Hodgkin's lymphoma
C. Amyloidosis (Correct Answer)
D. Malaria

Explanation: The term **'Lardaceous Spleen'** refers to a specific macroscopic pattern of **Amyloidosis** involving the spleen. [1] 1. **Why Amyloidosis is correct:** In systemic amyloidosis, amyloid proteins deposit in the splenic stroma [2]. There are two distinct patterns of deposition: * **Sago Spleen:** Amyloid is limited primarily to the splenic follicles (white pulp), appearing as translucent, grain-like granules resembling sago seeds. * **Lardaceous Spleen:** Amyloid deposits involve the **splenic sinuses and red pulp** (sinusoids). This results in massive splenomegaly with a firm, waxy, and map-like appearance on the cut surface, resembling "lard" (pig fat). 2. **Why other options are incorrect:** * **Chronic Myeloid Leukemia (CML):** Characterized by massive splenomegaly due to extramedullary hematopoiesis and leukemic infiltration, but it does not show the waxy, lardaceous appearance. * **Hodgkin’s Lymphoma:** Typically presents with a "Hard-bake spleen" (Marmorated appearance), where white nodules of tumor tissue are scattered against a dark red background. * **Malaria:** Causes "Big Spleen Disease" (Tropical Splenomegaly Syndrome). The spleen is usually soft and congested in acute cases and becomes firm and slate-grey/black (due to hemozoin pigment) in chronic cases. **High-Yield Clinical Pearls for NEET-PG:** * **Staining:** Amyloid shows **Apple-green birefringence** under polarized light when stained with **Congo Red**. [1] * **Sago vs. Lardaceous:** Remember **S**ago = **S**plenic follicles (White pulp); **L**ardaceous = **L**arge deposits/Sinusoids (Red pulp). * **Most common organ involved:** Kidney is the most common and most serious organ involved in systemic amyloidosis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 264-269. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 135-136.

Question 1120: In comparison to hyperplasia, hypertrophy is defined as?

A. Increase in cell size and number
B. Increase in cell size without an increase in number (Correct Answer)
C. Increase in cell number without an increase in size
D. Increase in cell size and decrease in number

Explanation: **Explanation:** Cellular adaptation occurs in response to physiological or pathological stress. The fundamental difference between hypertrophy and hyperplasia lies in the mechanism of organ enlargement [1]. **1. Why Option B is Correct:** **Hypertrophy** is defined as an increase in the **size of cells**, resulting in an increase in the size of the organ [3]. It occurs due to the increased synthesis of structural proteins and organelles [2]. Crucially, in pure hypertrophy, there is **no new cell formation** (no change in cell number) [3]. This typically occurs in "permanent" cells (like cardiac and skeletal muscle) that have limited capacity for division. **2. Analysis of Incorrect Options:** * **Option A:** This describes a combination of hypertrophy and hyperplasia. While both often occur together (e.g., the pregnant uterus), the specific definition of hypertrophy excludes the increase in number [2], [3]. * **Option C:** This is the definition of **Hyperplasia**, which is an increase in the number of cells resulting from the proliferation of differentiated cells or stem cells [3]. * **Option D:** This is physiologically incorrect. A decrease in cell number combined with an increase in size does not define a standard adaptive process; a decrease in cell number/size is generally termed **Atrophy**. **3. NEET-PG Clinical Pearls:** * **Pure Hypertrophy:** Occurs in **Left Ventricular Hypertrophy (LVH)** due to hypertension. Cardiac myocytes cannot divide; they only grow larger [2]. * **Pure Hyperplasia:** Occurs in **Endometrial Hyperplasia** or viral warts (HPV). * **Combined Hypertrophy & Hyperplasia:** The most classic example is the **Uterus during pregnancy** (stimulated by estrogen) [2]. * **Mechanism:** Hypertrophy is mediated by PI3K/AKT pathways and G-protein coupled receptors, leading to increased protein synthesis [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 87-88. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, pp. 45-46. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 85-87.

Practice by Chapter

Cell Injury and Cell Death

Practice Questions

Adaptations of Cellular Growth

Practice Questions

Accumulations and Deposits

Practice Questions

Acute and Chronic Inflammation

Practice Questions

Tissue Repair and Wound Healing

Practice Questions

Hemodynamic Disorders

Practice Questions

Genetic Disorders

Practice Questions

Environmental Pathology

Practice Questions

Nutritional Diseases

Practice Questions

Molecular Basis of Disease

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free