General Pathology Practice Questions

Q: What is the characteristic finding of sweat chloride levels in patients with cystic fibrosis?

Increased. **Explanation:** The correct answer is **B (Increased)**. **Pathophysiology:** Cystic Fibrosis (CF) is caused by a mutation in the **CFTR (Cystic Fibrosis Transmembrane Conductance Regulator)** gene. The CFTR protein functions differently depending on the tissue. In the **sweat glands**, its primary role is the **reabsorption** of chloride ions from the primary secretion back into the ductal cells [1]. Sodium follows chloride to maintain electrical neutrality. In CF patients, the defective CFTR channel cannot reabsorb chloride; consequently, chloride remains in the sweat, leading to an abnormally high concentration of salt (NaCl) on the skin surface [1]. **Analysis of Incorrect Options:** * **Option A (Decreased):** This is incorrect because the defect lies in the inability to *reabsorb* chloride from the lumen. Decreased levels are not seen in CF [1]. * **Option C & D (No change / May increase or decrease):** Sweat chloride levels are consistently elevated in classic CF, making these options clinically inaccurately. **High-Yield NEET-PG Pearls:** * **Gold Standard Diagnosis:** The **Pilocarpine Iontophoresis Sweat Test** is the diagnostic test of choice. A chloride concentration **>60 mmol/L** is diagnostic of CF. * **Tissue Paradox:** Remember the "CFTR Paradox"—in the **respiratory and GI tracts**, CFTR failure leads to decreased chloride *secretion* (causing thick, dehydrated mucus), whereas in **sweat glands**, it leads to decreased chloride *reabsorption* [1]. * **Genetics:** Most common mutation is **ΔF508** (Class II defect: protein misfolding and degradation). * **Clinical Sign:** Mothers often report that the infant "tastes salty" when kissed. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Lumen Of Sweat Duct, pp. 475-476.

Q: Which of the following is NOT a characteristic of Turner syndrome?

True hermaphrodism. **Explanation:** **Turner Syndrome (45,X)** is the most common sex chromosome abnormality in females, characterized by the complete or partial absence of one X chromosome [1]. **Why "True Hermaphroditism" is the correct answer:** True Hermaphroditism (now termed **Ovotesticular Disorder of Sex Development**) is defined by the presence of both ovarian and testicular tissue in the same individual. Turner syndrome patients, however, do not possess testicular tissue. Instead, they have **"streak ovaries"** (dysgenetic gonads) where follicles are absent and replaced by fibrous stroma [1]. They are phenotypically female but remain sexually infantile. **Why the other options are incorrect:** * **Short Stature:** This is the most consistent clinical feature of Turner syndrome, primarily due to the haploinsufficiency of the **SHOX gene** located on the short arm of the X chromosome [1]. * **Webbed Neck (Cystic Hygroma/Pterygium colli):** This results from lymphatic obstruction during fetal development. Other related features include a low posterior hairline and a broad "shield-shaped" chest [1]. * **Dysgenetic Gonads:** As mentioned, accelerated oocyte loss leads to fibrous "streak" ovaries, resulting in primary amenorrhea and infertility. **High-Yield Clinical Pearls for NEET-PG:** * **Karyotype:** 45,X is the most common (50%), but mosaics (e.g., 45,X/46,XX) and structural abnormalities (Isochromosome Xq) also occur [1]. * **Cardiac Associations:** Bicuspid aortic valve (most common) and Coarctation of the aorta (pre-ductal). * **Renal Association:** Horseshoe kidney. * **Biochemical Markers:** Elevated LH and FSH levels (Hypergonadotropic hypogonadism) due to lack of feedback inhibition from estrogen. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 175-177.

Q: Amyloid deposits stain positively with all of the following reagents except?

Methenamine silver. **Explanation:** The correct answer is **Methenamine silver** because it is primarily used to stain fungi, basement membranes, and certain opportunistic pathogens (like *Pneumocystis jirovecii*), but it does not have an affinity for amyloid fibrils. **Why the other options are incorrect:** * **Congo Red:** This is the gold standard for amyloid staining. Under ordinary light, it stains amyloid pink-red [1]. Under polarized light, it demonstrates the pathognomonic **apple-green birefringence** due to the cross-beta-pleated sheet configuration of amyloid fibrils [1]. * **Crystal Violet (and Methyl Violet):** These are metachromatic stains. Amyloid reacts with these dyes to produce a rose-pink or reddish-violet color, contrasting with the blue/purple color of the dye itself. * **Thioflavin T (and S):** These are fluorescent dyes. When viewed under a fluorescence microscope, Thioflavin T gives a bright yellow-green fluorescence. This method is highly sensitive but less specific than Congo Red. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Type:** Systemic AL (Light chain) amyloidosis is the most common primary type; AA (Amyloid Associated) is secondary to chronic inflammation. * **Diagnosis:** Abdominal fat pad aspiration or rectal biopsy are the preferred initial screening sites (high sensitivity). * **H&E Appearance:** On standard Hematoxylin and Eosin stain, amyloid appears as an **extracellular, amorphous, eosinophilic (pink), hyaline** material [2]. * **Other Stains:** Sirius Red is another stain that can be used to demonstrate birefringence similar to Congo Red. **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] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, pp. 580-581.

Question 1

Time taken by tissue to develop frank necrosis is approximately:

Accepted Answer

4 hours

Answer

30 minutes

Answer

1 hour

Answer

2 hours

Question 2

HER-2/NEU receptor gene mutation is seen in which cancer?

Accepted Answer

Breast cancer

Answer

Squamous cell carcinoma

Answer

Glioblastoma

Answer

All of the above

Question 3

What is the characteristic finding of sweat chloride levels in patients with cystic fibrosis?

Accepted Answer

Increased

Answer

Decreased

Answer

No change

Answer

May increase or decrease

Question 4

Myasthenia gravis is caused by dysfunction of -

Accepted Answer

Thymus gland

Answer

Pineal gland

Answer

Pituitary gland

Answer

Parathyroid gland

Question 5

What is the best prognostic type of Hodgkin's disease?

Accepted Answer

Lymphocyte predominant

Answer

Lymphocyte depletion

Answer

Mixed cellularity

Answer

Nodular sclerosis

Question 6

What is the best investigation for diagnosing amyloidosis?

Accepted Answer

Rectal biopsy

Answer

Colonoscopy

Answer

CT scan

Answer

Upper GI endoscopy

Question 7

Which of the following statements about amyloidosis is false?

Accepted Answer

It is made of proteins that calcify.

Answer

It can be a complication of chronic infections.

Answer

It is associated with extracellular eosinophilic hyaline material.

Answer

It shows apple-green birefringence under polarized light.

Question 8

Which of the following is NOT a characteristic of Turner syndrome?

Accepted Answer

True hermaphrodism

Answer

Short stature

Answer

Webbed neck

Answer

Dysgenetic gonads

Question 9

Amyloid deposits stain positively with all of the following reagents except?

Accepted Answer

Methenamine silver

Answer

Congo-red

Answer

Crystal violet

Answer

Thioflavin T

Question 10

Which of the following events occurs earliest in wound healing?

Accepted Answer

Neutrophils line the wound edge

Answer

A thin continuous epithelial cover appears

Answer

Fibroblasts lay down collagen fibers

Answer

Granulation tissue fills the wound

General Pathology — MCQs

General Pathology — MCQs

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