FMGE 2017 — Pathology
5 Previous Year Questions with Answers & Explanations
Rolling of leucocytes on endothelial cells is mediated by which of the following proteins?
Which of the following conditions is characterized by the presence of hyaline deposits in alveolar walls?
All of the following special histology stains are used to demonstrate H. pylori in gastric biopsies, except:
Most common type of lesion in Pott's spine:
Which of the following breast lesions characteristically shows central necrosis with calcification?
FMGE 2017 - Pathology FMGE Practice Questions and MCQs
Question 1: Rolling of leucocytes on endothelial cells is mediated by which of the following proteins?
- A. Integrins
- B. Transferrin
- C. PECAM-1
- D. Selectins (Correct Answer)
Explanation: **Selectins** - **Selectins** mediate the initial, weak and transient adhesion of **leukocytes** to the **endothelial cells** lining blood vessels [1]. - This interaction slows down the leukocytes, causing them to **roll** along the vascular endothelium as a prerequisite for **extravasation** [1]. *Integrins* - **Integrins** are responsible for the **firm adhesion** of leukocytes to endothelial cells, but not the rolling [1]. - They bind to **ICAM-1 (intercellular adhesion molecule-1)** on endothelial cells, leading to stable arrest of the leukocyte [1]. *PECAM-1* - **PECAM-1 (Platelet Endothelial Cell Adhesion Molecule-1)** plays a role in **diapedesis** or **transmigration**, the movement of leukocytes *through* the endothelial cell junctions [1]. - It facilitates the passage of the leukocyte by interacting with PECAM-1 on the endothelial cells, but does not mediate rolling [1]. *Transferrin* - **Transferrin** is an iron-binding protein found in blood plasma that regulates free **iron levels** in the body. - It is crucial for **iron transport** and metabolic processes but has no direct role in leukocyte adhesion or rolling on endothelial cells. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 87-89.
Question 2: Which of the following conditions is characterized by the presence of hyaline deposits in alveolar walls?
- A. Asthma
- B. Hyaline membrane disease (Correct Answer)
- C. Chronic bronchitis
- D. Interstitial lung disease
Explanation: ***Hyaline membrane disease*** - This condition is pathologically characterized by the presence of **eosinophilic (hyaline) membranes** lining the distal airspaces, which are composed of fibrin, cellular debris, and necrotic cells [1]. - These **hyaline deposits obstruct gas exchange** and are a hallmark of **acute lung injury** in neonates due to surfactant deficiency [2]. *Asthma* - Characterized by **bronchoconstriction**, **mucus plugging**, and **airway inflammation**, but not hyaline deposits in alveolar walls. - Pathologically, there is hyperplasia of goblet cells, hypertrophy of bronchial smooth muscle, and eosinophilic infiltration. *Chronic bronchitis* - Defined by **chronic productive cough** due to hypertrophy of mucous glands and increased mucus production in the bronchi, not alveolar hyaline deposits. - It primarily affects the **large airways** and is associated with chronic inflammation and airway obstruction. *Interstitial lung disease* - Involves inflammation and fibrosis of the **interstitium of the lung**, leading to impaired gas exchange. - While it causes architectural distortion, **hyaline deposits** in the alveolar walls are not a defining pathological feature. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 679-681. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, p. 466.
Question 3: All of the following special histology stains are used to demonstrate H. pylori in gastric biopsies, except:
- A. Giemsa stain
- B. Fite's stain (Correct Answer)
- C. Warthin-Starry stain
- D. Modified Steiner's stain
Explanation: ***Fite's stain*** - **Fite's stain** (or Fite-Faraco stain) is a modified acid-fast stain primarily used to detect **mycobacteria**, particularly **Mycobacterium leprae**, in tissue sections [2]. - It is not used for the identification of **Helicobacter pylori**. *Giemsa stain* - **Giemsa stain** is a common special stain used to visualize **Helicobacter pylori** directly in gastric biopsies due to its ability to stain the bacterial cytoplasm a characteristic **blue color**. - It works by staining the cytoplasmic and nuclear components of cells, making bacteria and inflammatory cells easily identifiable. *Modified Steiner's stain* - **Modified Steiner's stain** is a silver impregnation stain used to demonstrate spirochetes and other bacteria, including **Helicobacter pylori**, by staining them **black**. - It involves a silver solution that precipitates onto the bacterial surface, followed by a reducing agent to visualize the organisms. *Warthin-Starry stain* - The **Warthin-Starry stain** is another silver impregnation method widely employed for detecting spirochetes and bacteria like **Helicobacter pylori** in tissue [1]. - It renders the bacteria visible as **black** or dark brown structures against a pale yellow background, providing excellent contrast [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, p. 771. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 385-386.
Question 4: Most common type of lesion in Pott's spine:
- A. Posterior
- B. Central
- C. Paradiscal (Correct Answer)
- D. Anterior
Explanation: ***Paradiscal*** - **Paradiscal lesions** are the most characteristic and common type of lesion in Pott's spine (approximately 50% of cases), preferentially affecting the anterior vertebral body adjacent to the intervertebral disc [1]. - This location is rich in **vascularity**, allowing Mycobacterium tuberculosis to spread more easily and cause significant destruction of the vertebral bodies and discs [1]. - Typically results in **angular kyphosis (gibbus deformity)** due to anterior vertebral collapse. *Posterior* - **Posterior lesions** affect the posterior elements of the vertebrae including the pedicles, laminae, and spinous processes. - This is the **rarest type** of tuberculous spinal involvement. - May present with neurological deficits due to posterior encroachment on the spinal canal. *Central* - A **central lesion** in Pott's spine involves primarily the vertebral body itself, without specific early involvement of the disc space or adjacent vertebrae. - This type is less common than paradiscal lesions and typically leads to **vertebra plana** (flat vertebra) or uniform **compression fracture** rather than angular kyphosis. *Anterior* - **Anterior lesions** affect the front part of the vertebral body and can lead to a wedge-shaped collapse. - While the anterior column is frequently involved, the term "anterior" is less specific than "paradiscal" in describing the most common initial location that characteristically spreads to the intervertebral disc space. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, pp. 1197-1198.
Question 5: Which of the following breast lesions characteristically shows central necrosis with calcification?
- A. Cribriform sub type of DCIS
- B. Lobular carcinoma in situ
- C. Colloid carcinoma
- D. Comedo sub type of DCIS (Correct Answer)
Explanation: ***Comedo sub type of DCIS*** - This subtype is characterized by high-grade pleomorphic tumor cells with **central necrosis** within the ducts [1]. - The necrotic debris often calcifies, leading to characteristic **microcalcifications** visible on mammograms [2]. *Cribriform sub type of DCIS* - This subtype features uniform cells forming gland-like spaces within the ducts, but **typically lacks significant central necrosis** and extensive calcification [1]. - It usually presents with a **low nuclear grade** and less aggressive features compared to comedo DCIS [1]. *Lobular carcinoma in situ* - Characterized by small, discohesive cells filling and expanding the acini of the lobules, but it **does not involve ductal necrosis or calcification**. - It is often an **incidental finding** and represents a marker for increased risk of invasive carcinoma in either breast, rather than an obligate precursor lesion visible with calcifications. *Colloid carcinoma* - This is a type of **invasive ductal carcinoma** where tumor cells float in abundant extracellular mucin. - While it is an invasive cancer, it does not typically present with the extensive **ductal necrosis and calcification** seen in comedo DCIS. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Breast, pp. 1062-1064. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 452-453.