Block 11 - Week 14 - CV & Respiratory Clinical Application
Questions and Answers
- 1.
A 35-year-old man returned last weekend from a vacation in Kenya, where he went on safari with his wife. He presents with fever, chills, headache, nausea, and weakness. On physical examination, he is found to have an enlarged, tender lymph node in his groin. A bipolar-staining, Gram-negative rod is isolated from blood cultures and culture of an aspirate from the lymph node. Which of the following virulence factors is important in the transmission of the causative agent by the vector?
- A.
Plasminogen activator protease
- B.
Capsule
- C.
Endotoxin
- D.
Outer membrane proteins
- E.
Coagulase
Correct Answer
E. CoagulaseExplanation
Coagulase is an enzyme produced by certain bacteria, including Staphylococcus aureus, which causes blood to clot. In the context of vector transmission, coagulase is important because it helps the bacteria form a protective clot around itself, allowing it to avoid being destroyed by the host's immune system. This clot can also facilitate the bacteria's attachment to the vector, such as a mosquito, enabling its transmission to another host. Therefore, coagulase is an important virulence factor for the causative agent in this case.Rate this question:
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- 2.
A 25-year-old African man living in a village in Zimbabwe without access to health care developed a 6-month-long illness characterized by fever, anorexia, cough, hemoptysis, and 50-pound weight loss. He was transported to a distant clinic where a x-ray showed bilateral cavitary pneumonia in his upper lobes. He died the next day. What would you expect the lungs to show at autopsy?
- A.
Ghon complex with fibrosis and large mediastinal lymph nodes
- B.
Ischemic necrosis with blackened upper lobes
- C.
Fungal hyphae invading blood vessels
- D.
Multiple abscesses containing polymorphonuclear leukocytes and foul-smelling pus
- E.
Caseous necrosis and Langhan’s giant cells
Correct Answer
E. Caseous necrosis and Langhan’s giant cellsExplanation
The given scenario describes a 25-year-old African man with a 6-month-long illness characterized by symptoms such as fever, anorexia, cough, hemoptysis, and weight loss. The x-ray showed bilateral cavitary pneumonia in the upper lobes of the lungs. The patient unfortunately died the next day. Based on these findings, it is likely that the lungs would show caseous necrosis and Langhan's giant cells at autopsy. This is indicative of tuberculosis, a bacterial infection caused by Mycobacterium tuberculosis, which commonly presents with cavitary lesions in the lungs and caseous necrosis, a form of necrotic tissue resembling cheese. Langhan's giant cells are a characteristic feature of tuberculosis.Rate this question:
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- 3.
An old hypertensive man presents with shortness of breath and a left pleural effusion. The pleural fluid is clear, serous, has a specific gravity of 1012 and shows low protein content. Cytology reveals only a few mesothelial cells. The pleural effusion is MOST LIKELY due to:
- A.
Bronchopneumonia
- B.
Lobar pneumonia
- C.
Left sided heart failure
- D.
Pulmonary tuberculosis
- E.
Bronchogenic carcinoma
Correct Answer
C. Left sided heart failureExplanation
The most likely cause of the old hypertensive man's shortness of breath and left pleural effusion is left sided heart failure. This is supported by the clear, serous pleural fluid with low protein content, which is characteristic of a transudative effusion seen in heart failure. The presence of only a few mesothelial cells on cytology suggests that there is no active infection or malignancy causing the effusion. Additionally, the patient's history of hypertension further supports the diagnosis of heart failure as the underlying cause.Rate this question:
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- 4.
A 58-year-old man has observed increasing dyspnea and 30 pound weight loss over the past month. He tells his physician that he has always tried to keep fit through exercise and healthy eating habits and does not smoke or drink. Further history taking reveals that he worked in a naval shipyard about 30 years ago at which time his duties included applying asbestos insulation to the ship’s lead piping. At this point, his physician suspects:
- A.
Hypersensitivity pneumonitis related to lead exposure
- B.
Mesothelioma
- C.
Bronchial asthma
- D.
Viral pneumonia
- E.
Chronic bronchitis
Correct Answer
B. MesotheliomaExplanation
The patient's history of working in a naval shipyard and being exposed to asbestos insulation suggests that he may have developed mesothelioma. Mesothelioma is a type of cancer that is commonly caused by asbestos exposure. The symptoms of increasing dyspnea and weight loss are also consistent with mesothelioma. Other options such as hypersensitivity pneumonitis, bronchial asthma, viral pneumonia, and chronic bronchitis are less likely given the patient's history of asbestos exposure.Rate this question:
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- 5.
A 20-year-old man accidentally drives his car into a brick wall and sustains severe chest injuries including several rib fractures, hemothorax and a collapsed lung on the side of the hemothorax. The lung has almost certainly collapsed on the basis of:
- A.
Ruptured bullae
- B.
Air embolism
- C.
Compressive atelectasis
- D.
Bone marrow embolism
- E.
Absorptive atelectasis
Correct Answer
C. Compressive atelectasisExplanation
The lung has almost certainly collapsed due to compressive atelectasis. This occurs when there is external pressure on the lung, causing it to collapse. In this case, the severe chest injuries, including rib fractures, would likely cause compression on the lung, leading to its collapse. Ruptured bullae, air embolism, bone marrow embolism, and absorptive atelectasis are not the most likely causes in this scenario.Rate this question:
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- 6.
Your patient is an 82- year old female who after a lifetime of cigarette smoking had been diagnosed with COPD. She has been living at home, but has just arrived at the hospital presenting with dyspnea, a fever of 102oF and considerable distress. The Gram-stained sputum shows a predominance of Gram-negative diplococci. Which organism is most likely to be causing the patient’s condition?
- A.
Neisseria meningitides
- B.
Moraxella catarrhalis
- C.
Haemophilus influenzae type b
- D.
Streptococcus pneumoniae
Correct Answer
B. Moraxella catarrhalisExplanation
Moraxella catarrhalis is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system, and joints of humans. It causes the infection of the host cell by sticking to the host cell using a Trimeric Autotransporter Adhesins (TAA).Rate this question:
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- 7.
A 65-year-old textile worker has had no major medical problems prior to the past year, when he noted increasing malaise along with a 7 kg weight loss. He is a non-smoker but enjoys at least 5 drinks a day. On physical examination, he has non-tender supraclavicular lymphadenopathy. The lungs are clear to auscultation but chest x-ray shows multiple solid nodules ranging from 1 to 3 cm scattered throughout all lung fields. No infiltrates or areas of consolidation are noted. Laboratory studies show Hgb 10.6 g/dL, Hct 30.7%, MCV 79 fL, and WBC count 6280/microliter. Which of the following pathologic processes in his lungs is most likely to account for these findings?
- A.
Pulmonary infarctions
- B.
Foreign body aspiration
- C.
Metastatic carcinoma
- D.
Sarcoidosis
- E.
Silicosis
Correct Answer
C. Metastatic carcinomaExplanation
The patient's history of weight loss, malaise, and supraclavicular lymphadenopathy, along with the presence of multiple solid nodules on chest x-ray, suggests a malignant process. The fact that the nodules are scattered throughout all lung fields and there are no infiltrates or areas of consolidation makes metastatic carcinoma the most likely explanation. Pulmonary infarctions would present with a different clinical picture, such as pleuritic chest pain and hemoptysis. Foreign body aspiration would typically present with localized symptoms and findings. Sarcoidosis would show bilateral hilar lymphadenopathy and pulmonary infiltrates. Silicosis would have a history of occupational exposure to silica.Rate this question:
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- 8.
A 34-year-old man with a 10 kg weight loss over the past 3 months now has had worsening fever, non-productive cough, and dyspnea for the past 3 days. His temperature is 38.2 C and there are diffuse rales in both lungs on auscultation. A chest radiograph shows patchy infiltrates in both lungs. Laboratory studies show a WBC count of 3250/microliter with differential of 78 segs, 3 bands, 5 lymphs, 11 monos, 2 eosinophils, and 1 basophil, Hgb 111.8 g/dL, Hct 35.4%, MCV 91 fL, and platelet count 317,000/microliter. His CD4 lymphocyte count is 79/microliter. Cryptosporidium organisms are found in a stool specimen. A bronchoalveolar lavage (BAL) is performed, yielding fluid that microscopically demonstrates pink, foamy exudate with little inflammation. Which of the following additional findings on microscopic examination is he most likely to have in the BAL specimen?
- A.
Acid fast bacilli
- B.
Branching septate hyphae
- C.
GMS positive cyst-like organisms
- D.
Hemosiderin-laden macrophages
- E.
Short gram- positive rods
Correct Answer
C. GMS positive cyst-like organismsExplanation
The patient's clinical presentation, including weight loss, fever, cough, and dyspnea, along with the presence of diffuse rales in both lungs and patchy infiltrates on chest radiograph, suggests a pulmonary infection. The low CD4 lymphocyte count indicates immunosuppression, which increases the risk of opportunistic infections. The finding of Cryptosporidium organisms in the stool specimen further supports the diagnosis of an opportunistic infection. The most likely finding on microscopic examination of the bronchoalveolar lavage (BAL) specimen would be GMS positive cyst-like organisms, as Cryptosporidium is a protozoan parasite that forms cysts in the gastrointestinal tract and can be detected in various body fluids, including respiratory secretions.Rate this question:
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- 9.
A 50 year old male comes to you for routine physical examination. He tells you that for the past 4 months he has been gradually decreasing hid activity because he gets breathless. You note a smell of tobacco on his fingers and that there is clubbing. Which of the following X-ray findings would be consistent with this presentation?
- A.
Consolidation in the left lung base
- B.
A solitary nodule in the Right upper lobe
- C.
Cavitation in the Right middle lobe
- D.
A congenital bulae in the left upper lobe
Correct Answer
B. A solitary nodule in the Right upper lobeExplanation
The presence of clubbing and a smell of tobacco on the patient's fingers suggests a chronic lung condition, most likely related to smoking. A solitary nodule in the right upper lobe on an X-ray would be consistent with this presentation, as it could indicate a potential lung tumor or malignancy. The other options do not directly correlate with the symptoms described.Rate this question:
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- 10.
A 60 year old chronic smoker with a diagnosis of COPD comes for evaluation due to difficulty sleeping at night and increasing dyspnea. One complication he is likely to have is:
- A.
Portal hypertension
- B.
Cor Pulmonale
- C.
Renal failure
- D.
DVT
Correct Answer
B. Cor PulmonaleExplanation
A 60-year-old chronic smoker with a diagnosis of COPD is likely to have cor pulmonale as a complication. Cor pulmonale is a condition characterized by right-sided heart failure due to long-term lung disease, such as COPD. The chronic smoking and COPD can lead to pulmonary hypertension, which in turn can cause the right side of the heart to work harder to pump blood into the lungs. Over time, this increased workload can lead to right-sided heart failure, known as cor pulmonale. This can result in symptoms such as difficulty sleeping at night and increasing dyspnea.Rate this question:
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