Respiratory Pathology Practice Questions

Q: Which of the following inhaled occupational pollutants produces extensive nodular pulmonary fibrosis?

Silica. **Explanation:** **Silica (Correct Answer):** Silicosis is characterized by the formation of discrete, concentric, **nodular pulmonary fibrosis**. When crystalline silica (SiO2) particles (0.5–3 µm) are inhaled, they are engulfed by alveolar macrophages. The silica particles are cytotoxic, causing the macrophages to rupture and release lysosomal enzymes and inflammatory cytokines (like TNF-alpha). This triggers a chronic fibroblastic response, resulting in the classic "silicotic nodule." These nodules primarily involve the upper lobes and can coalesce to form Progressive Massive Fibrosis (PMF). **Why other options are incorrect:** * **Asbestos:** Produces **diffuse interstitial fibrosis** (asbestosis) rather than nodular lesions. It primarily affects the lower lobes and is associated with pleural plaques and ferruginous bodies. * **Wood Dust:** Primarily associated with allergic rhinitis, occupational asthma, and specifically **Adenocarcinoma of the Nasal Cavity/Sinuses**, rather than extensive pulmonary fibrosis. * **Carbon:** Inhalation of coal dust leads to Coal Workers' Pneumoconiosis (CWP). While it can cause fibrosis, the hallmark lesion is the **"Coal Macule"** (accumulation of dust-laden macrophages). Extensive fibrosis only occurs in the complicated stage (PMF), but silica is the classic prototype for "nodular" fibrosis. **High-Yield Clinical Pearls for NEET-PG:** * **Radiology:** Silicosis shows "Egg-shell calcification" of hilar lymph nodes. * **Complication:** Silicosis significantly increases the risk of **Tuberculosis** (Silicotuberculosis) because silica impairs macrophage function. * **Occupations:** Sandblasting, stone cutting, mining, and glass manufacturing. * **Snowstorm Appearance:** Characteristic X-ray finding in silicosis.

Question 1

A 56-year-old chronic smoker has a mass resected from the bronchus. What is the most useful immunohistochemical marker for a proper diagnosis?

Accepted Answer

Cytokeratin

Answer

Vimentin

Answer

Epithelial membrane antigen

Answer

Leukocyte common antigen

Question 2

A 72-year-old man presents with a year of increasing dyspnea. Auscultation reveals decreased breath sounds on the right side of the chest. A chest radiograph shows a large pleural mass encasing the right lung. Exposure to which of the following metals is most likely associated with these findings?

Accepted Answer

Asbestos

Answer

Arsenic

Answer

Beryllium

Answer

Chromium

Question 3

Which of the following inhaled occupational pollutants produces extensive nodular pulmonary fibrosis?

Accepted Answer

Silica

Answer

Asbestos

Answer

Wood dust

Answer

Carbon

Question 4

Which of the following is NOT a histological feature of pulmonary hypertension?

Accepted Answer

Thrombi in pulmonary vasculature

Answer

Capillaritis of alveolar septa

Answer

Saddle thrombi in pulmonary trunk

Answer

All of the above

Question 5

Cough and sputum in COPD are primarily due to changes in which part of the respiratory system?

Accepted Answer

Large airways

Answer

Medium airways

Answer

Small airways

Answer

Lung parenchyma

Question 6

In a chronic smoker, which highly malignant, aggressive, and metastatic lung carcinoma is most commonly seen?

Accepted Answer

Small cell Carcinoma

Answer

Squamous cell Carcinoma

Answer

Adenocarcinoma

Answer

Large cell carcinoma

Question 7

All of the following are true regarding histological features of asbestosis, except:

Accepted Answer

Asbestos bodies consist of asbestos fibers coated with a proteinaceous material

Answer

Diffuse pulmonary interstitial fibrosis

Answer

Fibrosis begins around respiratory bronchioles and alveolar ducts and extends to involve adjacent alveolar sacs and alveoli

Answer

Pleural plaques are collections of dense collagen

Question 8

Which of the following is known to cause cavitating lung lesions?

Accepted Answer

Squamous cell carcinoma

Answer

Adenocarcinoma

Answer

Small cell carcinoma

Answer

Large cell carcinoma

Question 9

Distension of distant alveoli is seen in which type of emphysema?

Accepted Answer

Paraseptal emphysema

Answer

Irregular emphysema

Answer

Panacinar emphysema

Answer

Centriacinar emphysema

Question 10

All of the following statements are true regarding idiopathic pulmonary fibrosis, except:

Accepted Answer

Masson bodies are characteristic.

Answer

Pleural surfaces develop a "cobblestoned" appearance.

Answer

Areas of fibrosis occur preferentially in the lower lobes and subpleural regions.

Answer

Fibroblastic foci are the earliest lesion.

Respiratory Pathology — MCQs

Respiratory Pathology — MCQs

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