General Pathology Practice Questions

Q: Which intermediate filament is characteristic of fibroblasts?

Vimentin. **Explanation:** Intermediate filaments (IFs) are crucial components of the cytoskeleton that provide mechanical strength to cells. They are highly tissue-specific, making them excellent immunohistochemical (IHC) markers in diagnostic pathology. **Why Vimentin is correct:** **Vimentin** is the characteristic intermediate filament of **mesenchymal cells**. Since fibroblasts are the prototypical cells of mesenchymal origin (connective tissue), they express vimentin. In tumor pathology, Vimentin is used as a primary marker for **sarcomas** (malignancies of mesenchymal origin). **Analysis of Incorrect Options:** * **Lamin A:** These are nuclear intermediate filaments found in the **nuclear lamina** (inner lining of the nuclear envelope) of most differentiated somatic cells, not specific to the cytoplasmic cytoskeleton of fibroblasts. * **Desmin:** This is the marker for **muscle cells** (skeletal, cardiac, and smooth muscle). It is used clinically to identify tumors like rhabdomyosarcomas or leiomyosarcomas. * **Cytokeratin:** This is the characteristic marker for **epithelial cells**. It is the primary IHC marker used to diagnose **carcinomas**. **NEET-PG High-Yield Pearls:** * **Vimentin** is also positive in Melanoma, Renal Cell Carcinoma (RCC), and Endometrial Carcinoma (exceptions where epithelial tumors show vimentin). * **Glial Fibrillary Acidic Protein (GFAP):** Marker for astrocytes and ependymal cells (Glial tumors/Gliomas). * **Neurofilaments:** Marker for neurons and neural tumors (e.g., Neuroblastoma). * **Synaptophysin/Chromogranin:** Markers for neuroendocrine tumors.

Q: Compared to fresh blood, stored blood has:

High extracellular K+. **Explanation:** The storage of blood leads to a series of biochemical and morphological changes collectively known as the **"Storage Lesion."** **Why High Extracellular K+ is Correct:** The Na+/K+ ATPase pump on the red blood cell (RBC) membrane is temperature-dependent. During storage at 1–6°C, this pump becomes inactive. Consequently, potassium (K+) leaks out of the RBCs into the plasma (extracellular fluid), while sodium enters the cells. This results in a progressive increase in extracellular potassium levels over time, which can pose a risk of hyperkalemia during massive or pediatric transfusions. **Analysis of Incorrect Options:** * **A. More 2,3-DPG:** Levels of **2,3-Diphosphoglycerate (2,3-DPG) decrease** significantly during storage. This increases the affinity of hemoglobin for oxygen, causing a **left shift** in the oxygen dissociation curve and reducing oxygen delivery to tissues. * **C. High extracellular Hb:** While some hemolysis occurs, significant free hemoglobin is not a standard feature of properly stored blood unless the unit is expired or damaged. The increase in K+ is a much more consistent and clinically significant biochemical marker. * **D. Increased platelets:** Platelets are highly unstable at 1–6°C. Their viability and count decrease rapidly in stored whole blood; they lose function within 48–72 hours. **High-Yield Clinical Pearls for NEET-PG:** * **pH Changes:** Stored blood becomes more **acidic** due to the accumulation of lactate and pyruvate (anaerobic glycolysis). * **Clotting Factors:** Levels of labile factors (**Factor V and Factor VIII**) decrease significantly during storage. * **Storage Lesion Summary:** ↓ pH, ↓ 2,3-DPG, ↓ ATP, ↓ Glucose, **↑ Potassium**, and ↑ Lactate. * **Massive Transfusion Risk:** Can lead to hypocalcemia (citrate toxicity) and hyperkalemia.

Question 1

Cachexin is:

Accepted Answer

TNF

Answer

IL-2

Answer

IL-12

Answer

INF-gamma

Question 2

Edema is caused by all of the following mechanisms, EXCEPT:

Accepted Answer

Increased plasma proteins

Answer

Increased vascular permeability

Answer

Obstruction to lymphatic flow

Answer

Sodium retention

Question 3

Which intermediate filament is characteristic of fibroblasts?

Accepted Answer

Vimentin

Answer

Lamin A

Answer

Desmin

Answer

Cytokeratin

Question 4

Haemorrhagic infarction is seen in which of the following?

Accepted Answer

Central venous thrombosis

Answer

Venous thrombosis

Answer

Thrombosis

Answer

Embolism

Question 5

A 55-year-old male presented with dry mouth and rheumatoid arthritis with high titers of anti-SS-A and anti-SS-B antibodies. He was diagnosed with a minor salivary gland tumor. What is the earliest histologic finding in this condition?

Accepted Answer

Lymphocytes

Answer

Endothelial cells

Answer

Basophils

Answer

Eosinophils

Question 6

Supernumerary tooth, described as a 'tooth within a tooth', is most commonly seen in which of the following dental anomalies?

Accepted Answer

Maxillary lateral incisors

Answer

Mandibular second premolar

Answer

Mandibular incisors

Answer

Maxillary central and lateral incisors

Question 7

Which of the following is a predisposing factor for arterial thrombosis?

Accepted Answer

Homocysteinemia

Answer

Antithrombin III deficiency

Answer

Protein S deficiency

Answer

Protein C deficiency

Question 8

Which of the following is not considered a precancerous lesion?

Accepted Answer

Verrucous carcinoma

Answer

Lichen planus

Answer

Submucous fibrosis

Answer

Leukoplakia

Question 9

In wound healing, what is the correct sequence of cell appearance?

Accepted Answer

Platelet -> Neutrophils -> Macrophages -> Fibroblast

Answer

Macrophage -> Platelet -> Neutrophils -> Fibroblast

Answer

Neutrophils -> Macrophages -> Platelet -> Fibroblast

Answer

Platelet -> Macrophages -> Neutrophils -> Fibroblast

Question 10

Compared to fresh blood, stored blood has:

Accepted Answer

High extracellular K+

Answer

More 2,3-DPG

Answer

High extracellular Hb

Answer

Increased platelets

General Pathology — MCQs

General Pathology — MCQs

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