Internal Medicine Exam Pulmonary Disease 4 — Questions and Answers
Question 1: A patient presents with fever, productive cough, and right lower lobe consolidation on CXR. He lives in a nursing home. Which organism is the most likely causative pathogen?
- Mycoplasma pneumoniae
- Streptococcus pneumoniae (Correct answer)
- Legionella pneumophila
- Klebsiella pneumoniae
Correct answer: Streptococcus pneumoniae
Streptococcus pneumoniae remains the most common cause of community-acquired pneumonia (CAP) in all settings including nursing homes.
Question 2: A 52-year-old woman presents with exertional dyspnea, a loud P2, and right heart failure signs. Right heart catheterization shows mean PAP 38 mmHg, PCWP 10 mmHg. What is the diagnosis?
- Group 2 pulmonary hypertension (left heart disease)
- Group 1 pulmonary arterial hypertension (PAH) (Correct answer)
- Pulmonary venous hypertension
- Cor pulmonale from COPD
Correct answer: Group 1 pulmonary arterial hypertension (PAH)
PAH (Group 1) is defined by mean PAP ≥25 mmHg with PCWP ≤15 mmHg and elevated pulmonary vascular resistance without left heart disease.
Question 3: Which chest X-ray finding is most suggestive of a tension pneumothorax?
- Ipsilateral lung collapse with tracheal deviation toward the affected side
- Bilateral pleural effusions with blunting of costophrenic angles
- Ipsilateral lung collapse with tracheal deviation away from the affected side (Correct answer)
- Unilateral hilar enlargement
Correct answer: Ipsilateral lung collapse with tracheal deviation away from the affected side
Tension pneumothorax causes contralateral tracheal deviation and mediastinal shift away from the affected side due to positive pressure buildup.
Question 4: A 40-year-old woman with lupus presents with pleuritic chest pain and a friction rub. CXR shows a small pleural effusion. What is the expected pleural fluid finding?
- pH <7.2, glucose <60 mg/dL, LDH >1000
- Transudative fluid with protein <2.5 g/dL
- Exudative fluid meeting Light's criteria (Correct answer)
- Chylous fluid with triglycerides >110 mg/dL
Correct answer: Exudative fluid meeting Light's criteria
Lupus pleuritis produces an exudative pleural effusion meeting Light's criteria due to pleural inflammation from immune complex deposition.
Question 5: A 70-year-old lifelong smoker with a 50 pack-year history is screened by low-dose CT and found to have a 10 mm solid pulmonary nodule. What is the recommended next step per Fleischner Society guidelines?
- No follow-up needed
- Repeat CT in 3 months
- PET-CT scan or CT-guided biopsy (Correct answer)
- Immediate surgical resection
Correct answer: PET-CT scan or CT-guided biopsy
In a high-risk patient, a solid nodule ≥8 mm warrants PET-CT, CT-guided biopsy, or surgical resection for definitive characterization per Fleischner guidelines.
Question 6: Which finding is most characteristic of hypersensitivity pneumonitis (extrinsic allergic alveolitis)?
- Peripheral blood eosinophilia >25%
- Improvement of symptoms after antigen removal (Correct answer)
- Unilateral ground-glass opacity on HRCT
- Positive serum ANCA
Correct answer: Improvement of symptoms after antigen removal
Hypersensitivity pneumonitis is caused by inhaled antigens; the hallmark is symptomatic improvement upon removal of the offending antigen source.
Question 7: A 45-year-old man with HIV (CD4 count 60 cells/µL) presents with fever, non-productive cough, and progressive dyspnea. CXR shows bilateral interstitial infiltrates. LDH is elevated. What is the most likely diagnosis?
- Tuberculosis reactivation
- Pneumocystis jirovecii pneumonia (PCP) (Correct answer)
- Bacterial pneumonia with Streptococcus pneumoniae
- Cytomegalovirus pneumonitis
Correct answer: Pneumocystis jirovecii pneumonia (PCP)
PCP classically presents in severely immunocompromised HIV patients (CD4 <200) with bilateral interstitial infiltrates, elevated LDH, and gradual onset dyspnea.
Internal Medicine Exam Pulmonary Disease 4
A patient presents with fever, productive cough, and right lower lobe consolidation on CXR.
He lives in a nursing home.
Which organism is the most likely causative pathogen?