Pulmonology — MCQs

A 23-year-old woman presents with wheezing symptoms and shortness of breath on exertion, occurring primarily in the spring and resolving spontaneously. She is a nonsmoker with no personal or family history of atopy or asthma. Physical examination reveals normal vital signs and cardiac findings, with clear lungs on auscultation and no wheezing on forced expiration. What is the most likely mechanism of wheezing in this patient?

Q464Medium

A 63-year-old woman presents with acute shortness of breath. She has a recent diagnosis of breast cancer and is undergoing active treatment. Her vital signs are: blood pressure 120/80 mm Hg, pulse 100/min. Cardiac and pulmonary examinations are normal. There are no clinical signs of deep venous thrombosis (DVT). Which of the following investigations is most likely to rule out a pulmonary embolism (PE)?

Q465Medium

Which of the following is a clinical sign of tension pneumothorax?

Q466Easy

Which of the following is NOT a characteristic of ARDS?

Q467Medium

Which of the following features would be seen in a patient with suspected aspergillosis?

Q468Easy

Which of the following is false regarding the CURB-65 criteria used to assess pneumonia severity?

Q469Easy

What is the major risk factor for the development of a lung abscess?

Q470Medium

A 25-year-old man presents with a progressive illness of several days' duration characterized by nonproductive cough, fever, and malaise. A lateral view chest radiograph reveals platelike atelectasis. Elevated titers of cold agglutinins are detected. Which of the following is the most likely type of pneumonia in this patient?

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 461: What is the most common cause of pulmonary embolism?

A. Thrombosis of leg veins (Correct Answer)
B. Thrombosis of prostatic veins
C. Inferior vena cava thrombosis
D. Thrombosis of internal pudendal artery

Explanation: **Explanation:** **1. Why Option A is Correct:** Pulmonary Embolism (PE) is most commonly a complication of **Deep Vein Thrombosis (DVT)** [1]. Approximately 90% of all pulmonary emboli originate from the deep veins of the lower extremities. Specifically, thrombi originating in the **proximal leg veins** (popliteal, femoral, and iliac veins) are the most likely to embolize to the pulmonary arteries due to their large caliber and high blood flow. **2. Why the Other Options are Incorrect:** * **Option B & C:** While thrombosis of the prostatic veins or the Inferior Vena Cava (IVC) can lead to PE, they represent a much smaller percentage of cases compared to leg veins. IVC thrombosis is usually a secondary extension of lower limb DVT rather than a primary isolated cause. * **Option D:** Thrombosis of the internal pudendal **artery** cannot cause a pulmonary embolism. Emboli to the lungs must originate in the **venous system** or the right side of the heart to reach the pulmonary circulation. Arterial thrombi lead to localized ischemia or distal systemic infarction (e.g., stroke), not PE. **3. Clinical Pearls for NEET-PG:** * **Most common site:** Proximal deep veins of the leg (above the knee) are higher risk than calf veins. * **Virchow’s Triad:** The pathophysiology of DVT/PE involves Stasis, Endothelial Injury, and Hypercoagulability. * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA) is the investigation of choice for PE. * **ECG Finding:** The most common ECG finding is **Sinus Tachycardia**, while the most specific (though rare) is the **S1Q3T3 pattern**. * **Chest X-ray:** Usually normal, but may show **Hampton’s Hump** (wedge-shaped opacity) or **Westermark sign** (focal oligemia).

Question 462: A 60-year-old hypertensive male had a stroke 2 weeks prior to a sudden attack of dyspnea. The present ECG shows changes of S1 Q3 T3, and the V/Q pulmonary scan shows major areas of reduced perfusion. What is the probable diagnosis?

A. Pneumothorax
B. Congestive cardiac failure
C. Pulmonary thromboembolism (Correct Answer)
D. Psychogenic dysfunction

Explanation: ### Explanation **Correct Option: C. Pulmonary thromboembolism (PTE)** The clinical scenario presents a classic triad for Pulmonary Thromboembolism: 1. **Risk Factors:** The patient had a stroke 2 weeks ago, implying prolonged immobilization (Virchow’s Triad: Stasis) [2]. 2. **ECG Findings:** The **S1Q3T3 pattern** (prominent S wave in Lead I, Q wave and inverted T wave in Lead III) is a classic, though non-specific, sign of acute right heart strain seen in massive PTE [1]. 3. **V/Q Scan:** The presence of "major areas of reduced perfusion" with normal ventilation (implied mismatch) is the hallmark of PTE [1]. **Analysis of Incorrect Options:** * **A. Pneumothorax:** While it causes sudden dyspnea, it would typically present with pleuritic chest pain and hyper-resonance on percussion. ECG changes like S1Q3T3 and V/Q perfusion defects are not characteristic [3]. * **B. Congestive Cardiac Failure (CCF):** CCF usually presents with bilateral basal crepitations and orthopnea. A V/Q scan in CCF would show patchy, non-segmental defects rather than major perfusion-specific deficits [3]. * **D. Psychogenic dysfunction:** This is a diagnosis of exclusion. The objective ECG and V/Q scan findings definitively point toward an organic vascular pathology [3]. **High-Yield Pearls for NEET-PG:** * **Most common ECG finding in PTE:** Sinus tachycardia (S1Q3T3 is specific but less common) [1]. * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA). * **Chest X-ray signs:** Westermark sign (focal oligemia) and Hampton’s Hump (wedge-shaped opacity) [1]. * **Wells Score:** Used clinically to predict the probability of PE before ordering investigations. * **Treatment of Choice:** Hemodynamically stable patients are started on LMWH/Fondaparinux; unstable patients (massive PE) require thrombolysis [2].

Question 463: A 23-year-old woman presents with wheezing symptoms and shortness of breath on exertion, occurring primarily in the spring and resolving spontaneously. She is a nonsmoker with no personal or family history of atopy or asthma. Physical examination reveals normal vital signs and cardiac findings, with clear lungs on auscultation and no wheezing on forced expiration. What is the most likely mechanism of wheezing in this patient?

A. Elevated IgE levels
B. Mast cell instability
C. Nonspecific hyperirritability of the tracheobronchial tree (Correct Answer)
D. Disordered immediate hypersensitivity

Explanation: ### Explanation The patient presents with symptoms suggestive of **Intrinsic (Non-atopic) Asthma**. The hallmark of all forms of asthma, regardless of the trigger, is **nonspecific hyperirritability of the tracheobronchial tree** [1]. **1. Why Option C is Correct:** In this clinical scenario, the patient lacks a personal or family history of atopy (no eczema, allergic rhinitis, or hay fever) and has normal IgE levels (implied by the absence of atopy). This points toward intrinsic asthma [2]. The underlying pathophysiology in these patients involves an exaggerated bronchoconstrictor response to various stimuli (like cold air, exercise, or seasonal irritants). This "hyper-responsiveness" or "hyperirritability" is the physiological basis of the airway narrowing that leads to wheezing and dyspnea [1]. **2. Why Other Options are Incorrect:** * **Options A, B, and D:** These are all components of **Extrinsic (Atopic) Asthma**. This type is characterized by a Type I hypersensitivity reaction (disordered immediate hypersensitivity) mediated by IgE [2]. In atopic individuals, exposure to specific allergens leads to IgE-mediated mast cell degranulation. Since this patient has no history of atopy, these mechanisms are less likely to be the primary driver of her symptoms. **Clinical Pearls for NEET-PG:** * **Asthma Triad (Samter’s Triad):** Asthma, Aspirin sensitivity, and Nasal polyposis (a classic form of non-atopic asthma) [2]. * **Diagnosis:** The gold standard for diagnosing bronchial asthma is **Spirometry**, showing reversible airway obstruction (increase in FEV1 >12% and >200ml after bronchodilator). * **Methacholine Challenge:** Used when asthma is suspected but spirometry is normal; it specifically tests for the "bronchial hyper-responsiveness" mentioned in Option C [1]. * **Physical Exam:** A normal lung exam does not rule out asthma, as symptoms are often episodic and paroxysmal [3].

Question 464: A 63-year-old woman presents with acute shortness of breath. She has a recent diagnosis of breast cancer and is undergoing active treatment. Her vital signs are: blood pressure 120/80 mm Hg, pulse 100/min. Cardiac and pulmonary examinations are normal. There are no clinical signs of deep venous thrombosis (DVT). Which of the following investigations is most likely to rule out a pulmonary embolism (PE)?

A. Normal chest X-ray
B. Normal electrocardiogram (ECG)
C. Normal ventilation-perfusion lung scan (Correct Answer)
D. Normal ventilation scan

Explanation: **Explanation:** The patient presents with acute dyspnea and a high-risk factor (active malignancy), raising suspicion for **Pulmonary Embolism (PE)**. In the diagnostic workup of PE, the goal of certain tests is to "rule out" the condition with high negative predictive value. **Why Option C is Correct:** A **Normal Ventilation-Perfusion (V/Q) scan** essentially excludes the diagnosis of pulmonary embolism [2]. It has a very high negative predictive value (nearly 100%). If the distribution of radioactive tracer is uniform throughout the lung fields in both ventilation and perfusion phases, the probability of PE is clinically insignificant, regardless of the pre-test probability [2]. **Analysis of Incorrect Options:** * **A & B (Normal CXR and ECG):** These are frequently normal in patients with PE [1]. A normal CXR is actually a common finding (or may show non-specific signs like atelectasis) [1]. Similarly, the most common ECG finding in PE is sinus tachycardia; a completely normal ECG does not rule out the diagnosis [1]. * **D (Normal Ventilation Scan):** A ventilation scan alone only assesses airway patency. PE is a "perfusion defect" with preserved ventilation (mismatch). A normal ventilation scan does not provide information about the pulmonary vasculature. **NEET-PG High-Yield Pearls:** * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA) is the current investigation of choice for most patients [2]. * **V/Q Scan Indications:** Preferred in patients with **renal failure** (high creatinine), **contrast allergy**, or sometimes in **pregnancy** (lower fetal radiation dose compared to CTPA) [2]. * **D-Dimer:** Useful only to rule out PE in patients with **low/intermediate clinical probability** (Wells' Score). It has high sensitivity but low specificity. * **ECG Sign:** While sinus tachycardia is most common, the classic (but rare) sign is **S1Q3T3** [1].

Question 465: Which of the following is a clinical sign of tension pneumothorax?

A. Tracheal deviation to the contralateral side (Correct Answer)
B. Dullness to percussion
C. Increased breath sounds
D. Increased tactile vocal fremitus

Explanation: ### Explanation **Tension Pneumothorax** is a life-threatening emergency where a "one-way valve" mechanism allows air to enter the pleural space during inspiration but prevents it from escaping during expiration [1]. This leads to a rapid build-up of positive intrapleural pressure [1]. #### Why Option A is Correct: As the pressure in the affected pleural space exceeds atmospheric pressure, it causes a **mediastinal shift** [1]. This pressure pushes the trachea and the heart toward the opposite (healthy) side. Therefore, **tracheal deviation to the contralateral side** is a hallmark clinical sign of tension pneumothorax, indicating significant mass effect and impending hemodynamic collapse [1]. #### Why Other Options are Incorrect: * **B. Dullness to percussion:** In pneumothorax, the pleural space is filled with air, not fluid or solid tissue. This results in **hyper-resonance** on percussion. Dullness is characteristic of pleural effusion or consolidation. * **C. Increased breath sounds:** Air in the pleural space acts as an insulator, preventing the transmission of sound from the lung to the chest wall. Therefore, breath sounds are **absent or significantly diminished** on the affected side. * **D. Increased tactile vocal fremitus (TVF):** TVF is decreased when there is air or fluid between the lung and the chest wall. **Decreased TVF** is expected here; increased TVF is seen in conditions like lobar pneumonia (consolidation). #### High-Yield Clinical Pearls for NEET-PG: * **Clinical Diagnosis:** Tension pneumothorax is a **clinical diagnosis**. Never wait for an X-ray if you suspect it; immediate decompression is required [1]. * **Management:** The immediate treatment is **needle decompression**. According to updated ATLS guidelines, this is performed in the **5th intercostal space** just anterior to the mid-axillary line (the 2nd ICS in the mid-clavicular line is an alternative in children). This is followed by a formal tube thoracostomy (chest tube). * **Hemodynamics:** The shift in mediastinum compresses the superior/inferior vena cava, leading to decreased venous return, **hypotension**, and obstructive shock.

Question 466: Which of the following is NOT a characteristic of ARDS?

A. Dyspnea
B. Ability to maintain PaO2 on 100% oxygen (Correct Answer)
C. Bilateral crepitations
D. Bilateral opacities on X-ray

Explanation: **Explanation:** Acute Respiratory Distress Syndrome (ARDS) is characterized by acute-onset respiratory failure resulting from non-cardiogenic pulmonary edema. **Why Option B is correct:** The hallmark pathophysiology of ARDS is a **significant right-to-left intrapulmonary shunt**. In ARDS, alveoli are filled with fluid or have collapsed (atelectasis), meaning blood perfusing these areas never comes into contact with alveolar gas. Because this blood bypasses ventilated units, increasing the Fraction of Inspired Oxygen (FiO2) to 100% fails to significantly improve the partial pressure of arterial oxygen (PaO2). This is known as **refractory hypoxemia**, making the "ability to maintain PaO2" a false statement regarding ARDS. **Why the other options are incorrect:** * **A. Dyspnea:** This is the primary clinical symptom. Patients present with severe respiratory distress, tachypnea, and increased work of breathing due to low lung compliance. * **C. Bilateral crepitations:** On physical examination, diffuse crackles (crepitations) are typically heard due to the presence of alveolar fluid. * **D. Bilateral opacities on X-ray:** According to the **Berlin Criteria**, the presence of bilateral opacities on chest imaging (X-ray or CT) that are not fully explained by effusions, collapse, or nodules is a mandatory diagnostic requirement. **NEET-PG High-Yield Pearls:** * **Berlin Criteria:** 1) Acute onset (within 1 week); 2) Bilateral opacities; 3) Pulmonary edema not explained by heart failure (PCWP <18 mmHg); 4) PaO2/FiO2 ratio <300. * **Severity:** Mild (200–300), Moderate (100–200), Severe (<100). * **Management:** Low tidal volume ventilation (6 mL/kg) is the gold standard to prevent Volutrauma. * **Pathology:** The characteristic histological finding is **Diffuse Alveolar Damage (DAD)** with hyaline membrane formation.

Question 467: Which of the following features would be seen in a patient with suspected aspergillosis?

A. Serum precipitins for Aspergillus (Correct Answer)
B. Elevated serum IgE
C. Peripheral eosinophilia
D. All of the above

Explanation: ### Explanation The diagnosis of **Aspergillosis** depends heavily on the clinical subtype, which ranges from hypersensitivity reactions to invasive disease. In the context of this question, **Serum precipitins (IgG antibodies)** for *Aspergillus fumigatus* are the most characteristic feature across various forms, particularly **Aspergilloma** (fungal ball) and **Chronic Pulmonary Aspergillosis (CPA)**. #### Why Option A is correct: * **Serum Precipitins (IgG):** These are found in over 90% of patients with Aspergilloma and CPA. They indicate a chronic immune response to the presence of the fungus. While they can be present in Allergic Bronchopulmonary Aspergillosis (ABPA), they are the hallmark diagnostic feature for non-invasive, chronic forms. #### Why Options B, C, and D are incorrect: * **Elevated Serum IgE & Peripheral Eosinophilia:** These features are specific to **ABPA**, which is a hypersensitivity reaction seen in patients with asthma or cystic fibrosis. They are **not** typically seen in Aspergilloma or Invasive Aspergillosis. * Since IgE and eosinophilia are not universal features of all "suspected aspergillosis" cases (especially the common Aspergilloma), "All of the above" is incorrect. The question asks for a feature generally seen/characteristic of the infection's presence. #### High-Yield Clinical Pearls for NEET-PG: 1. **Aspergilloma:** Characterized by the **"Monod Sign"** or **"Air-crescent sign"** on X-ray (a gravity-dependent mass within a pre-existing cavity, usually from old TB). 2. **ABPA Diagnostic Criteria:** Look for asthma, fleeting pulmonary opacities, central bronchiectasis, and **Total IgE >1000 IU/mL**. 3. **Invasive Aspergillosis:** Occurs in immunocompromised patients (neutropenia). Look for the **"Halo Sign"** on CT and use **Galactomannan assay** for diagnosis. 4. **Drug of Choice:** **Voriconazole** is the gold standard for invasive disease; Itraconazole is used for ABPA and CPA.

Question 468: Which of the following is false regarding the CURB-65 criteria used to assess pneumonia severity?

A. Blood urea nitrogen > 7 mmol/L
B. Respiratory rate >= 30 breaths/min
C. Systolic blood pressure <= 100 mmHg (Correct Answer)
D. Diastolic blood pressure <= 60 mmHg

Explanation: The **CURB-65 score** is a validated clinical prediction rule used to determine the severity of Community-Acquired Pneumonia (CAP) and guide the site of care (outpatient vs. inpatient vs. ICU) [1]. ### **Why Option C is the Correct Answer (The False Statement)** In the CURB-65 criteria, the threshold for **hypotension** is defined as a **Systolic Blood Pressure (SBP) < 90 mmHg** or a **Diastolic Blood Pressure (DBP) ≤ 60 mmHg**. Option C states a threshold of ≤ 100 mmHg, which is incorrect and would lead to an overestimation of severity. ### **Analysis of Other Options (True Criteria)** * **A. Blood urea nitrogen > 7 mmol/L:** This is a correct component (**U**rea) [1]. In mg/dL, this corresponds to > 19 mg/dL. * **B. Respiratory rate ≥ 30 breaths/min:** This is a correct component (**R**espiratory rate) indicating significant respiratory distress. * **D. Diastolic blood pressure ≤ 60 mmHg:** This is a correct component (**B**lood pressure) representing hemodynamic instability. ### **The CURB-65 Breakdown** Each criteria carries 1 point [1]: 1. **C**onfusion (new onset) 2. **U**rea > 7 mmol/L (19 mg/dL) 3. **R**espiratory Rate ≥ 30/min 4. **B**lood Pressure (SBP < 90 or DBP ≤ 60 mmHg) 5. **Age ≥ 65** years ### **High-Yield Clinical Pearls for NEET-PG** * **Management Guide:** * **Score 0-1:** Low risk; consider outpatient treatment [1]. * **Score 2:** Moderate risk; consider short-stay inpatient observation [1]. * **Score ≥ 3:** Severe pneumonia; requires hospitalization (consider ICU if score is 4-5) [1]. * **CRB-65:** A modified version used in primary care settings where urea testing is unavailable. * **Limitation:** CURB-65 does not account for comorbidities or oxygenation (unlike the PSI/PORT score), which are also critical in management decisions.

Question 469: What is the major risk factor for the development of a lung abscess?

A. Pneumonia
B. Aspiration (Correct Answer)
C. Lung cancer
D. Tuberculosis

Explanation: **Explanation:** **1. Why Aspiration is the Correct Answer:** Aspiration of oropharyngeal secretions is the **most common and significant risk factor** for a primary lung abscess [1]. The underlying mechanism involves the inhalation of large amounts of anaerobic bacteria (normally present in gingival crevices) into the dependent segments of the lungs. This typically occurs in patients with an **altered state of consciousness** (e.g., alcoholism, seizures, general anesthesia, or drug overdose) or **dysphagia** [1]. The resulting necrotizing infection leads to parenchymal destruction and the formation of a cavity containing pus. **2. Why Other Options are Incorrect:** * **Pneumonia (A):** While a lung abscess can be a complication of pneumonia (especially if caused by *S. aureus* or *K. pneumoniae*) [3], most community-acquired pneumonias resolve without abscess formation. Aspiration remains the primary inciting event for the majority of cases. * **Lung Cancer (C):** Malignancy can cause an "obstructive" lung abscess by blocking a bronchus [2], but it is a less frequent cause compared to aspiration [1]. * **Tuberculosis (D):** TB typically causes "cavitary" lesions rather than acute pyogenic abscesses [2]. While it is a differential diagnosis for a lung cavity, it is not the leading risk factor for a classic lung abscess. **3. Clinical Pearls for NEET-PG:** * **Microbiology:** Most lung abscesses are **polymicrobial**, dominated by **anaerobes** (*Peptostreptococcus, Fusobacterium, Prevotella*) [1]. * **Common Site:** The **posterior segment of the right upper lobe** and the **superior segment of the right lower lobe** are the most frequent sites due to the vertical nature of the right main bronchus. * **Clinical Sign:** Patients often present with **foul-smelling (putrid) sputum** and dental caries/poor oral hygiene [1]. * **Treatment:** Prolonged antibiotics (e.g., Clindamycin or Beta-lactam/Beta-lactamase inhibitors) are the mainstay; surgical drainage is rarely required [1].

Question 470: A 25-year-old man presents with a progressive illness of several days' duration characterized by nonproductive cough, fever, and malaise. A lateral view chest radiograph reveals platelike atelectasis. Elevated titers of cold agglutinins are detected. Which of the following is the most likely type of pneumonia in this patient?

A. Bacterial pneumonia, most likely caused by S. pneumoniae
B. Hospital-acquired pneumonia, most likely caused by P. aeruginosa
C. Interstitial pneumonia, most likely caused by M. pneumoniae (Correct Answer)
D. P. jiroveci (carinii) pneumonia, most likely related to an immunocompromised state

Explanation: ### Explanation **1. Why the Correct Answer is Right:** The clinical presentation of a young adult with a subacute onset of nonproductive cough, fever, and constitutional symptoms (malaise) is classic for **Atypical Pneumonia**. The presence of **elevated cold agglutinin titers** (IgM antibodies that agglutinate RBCs at low temperatures) is a highly specific diagnostic clue for ***Mycoplasma pneumoniae***. Radiographically, atypical pneumonias typically present as **interstitial infiltrates** or "platelike" atelectasis rather than dense lobar consolidation [1]. *M. pneumoniae* is the most common cause of community-acquired pneumonia in school-aged children and young adults. **2. Why the Incorrect Options are Wrong:** * **Option A:** *S. pneumoniae* causes typical bacterial pneumonia, characterized by an acute onset, high fever, productive cough (rusty sputum), and **lobar consolidation** on X-ray [1]. It is not associated with cold agglutinins. * **Option B:** Hospital-acquired pneumonia (HAP) occurs ≥48 hours after admission. This patient’s presentation is community-acquired. *P. aeruginosa* typically affects patients with structural lung disease (e.g., cystic fibrosis) or those on ventilators [1]. * **Option D:** *Pneumocystis jirovecii* (PJP) presents with progressive dyspnea and dry cough, but it is almost exclusively seen in **immunocompromised** patients (e.g., HIV/AIDS with CD4 <200). While it shows interstitial patterns, it does not trigger cold agglutinins. **3. NEET-PG High-Yield Pearls:** * **"Walking Pneumonia":** A clinical term for *Mycoplasma* because patients often appear less ill than their radiographs suggest. * **Extrapulmonary Manifestations of *Mycoplasma*:** Bullous myringitis (ear pain), Stevens-Johnson Syndrome, hemolytic anemia (due to cold agglutinins), and meningoencephalitis. * **Treatment of Choice:** Macrolides (Azithromycin) or Tetracyclines (Doxycycline), as *Mycoplasma* lacks a cell wall and is resistant to Beta-lactams. * **Radiology:** "Dissociation between clinical signs and radiological findings" is a hallmark of atypical pneumonia.

Practice by Chapter

Obstructive Airway Diseases (Asthma, COPD)

Practice Questions

Interstitial Lung Diseases

Practice Questions

Pulmonary Infections

Practice Questions

Pulmonary Vascular Diseases

Practice Questions

Pleural Diseases

Practice Questions

Sleep-Disordered Breathing

Practice Questions

Respiratory Failure

Practice Questions

Mediastinal Disorders

Practice Questions

Occupational Lung Diseases

Practice Questions

Pulmonary Function Testing

Practice Questions

Bronchiectasis and Cystic Fibrosis

Practice Questions

Lung Cancer Approach

Practice Questions

Want unlimited practice?

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

Start For Free