Question 21
A 55-year-old woman has had fever and dyspnea for a month along with a 2 kg weight loss. On physical examination her temperature is 37.7 C. A chest radiograph shows a reticulonodular pattern along with prominent hilar lymphadenopathy. A transbronchial lung biopsy is performed, and microscopic examination shows no viral inclusions, no fungi, no acid fast bacilli, and no atypical cells. Which of the following diseases is she most likely to have?
A Silicosis
B Sarcoidosis
C Asbestosis
D Tuberculosis
E Usual interstitial pneumonitis
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(B) CORRECT. The symptoms and signs are classic. Sarcoidosis often involves the hilar lymph nodes.
(A) Incorrect. Silicosis produces an interstitial lung disease with a reticulonodular pattern with silicotic nodules.
(C) Incorrect. Pleural plaques are a typical finding for asbestosis.
(D) Incorrect. Special stains on the lung biopsy would have shown acid fast bacilli.
(E) Incorrect. UIP is a form of restrictive lung disease with interstitial fibrosis.
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Question 22
A 55-year-old man has been a cigarette smoker for the past 39 years. He has noted some blood-streaked sputum on coughing during the past week. He also has back pain. A chest radiograph shows a small 3 cm right hilar mass with several 1 to 2 cm peripheral lung nodules. A bone scan reveals multiple areas of increased uptake in the vertebrae, ribs, and pelvis. A sputum cytology reveals the presence of clusters of small cells having hyperchromatic nuclei and almost no cytoplasm. Which of the following laboratory test findings is he most likely to have as a consequence of his lung disease?
A Positive antinuclear antibody
B Platelet count of 55,000/microliter
C Plasma cortisol at 8 am of 5 microgm/dL
D Serum sodium of 113 mmol/L
E Hyperuricemia
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(D) CORRECT. He has a small cell anaplastic carcinoma with widespread metastases. The syndrome of inappropriate ADH producing hyponatremia is one form of paraneoplastic syndrome seen with this particular carcinoma.
(A) Incorrect. Paraneoplastic syndromes are not generally associated with autoimmune diseases or markers.
(B) Incorrect. Thrombocytopenia is not a feature of a paraneoplastic syndrome.
(C) Incorrect. One form of paraneoplastic syndrome is Cushing syndrome from ectopic ACTH production, which should elevate the serum cortisol.
(E) Incorrect. The turnover rate of lung cancers is generally not high enough to elevate the uric acid.
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Question 23
A 40-year-old woman has had a high fever for a week, accompanied by a cough productive of yellowish sputum. On physical examination her temperature is 38.2 C. There are diffuse rales in all lung fields. Her chest radiograph reveals patchy infiltrates in all lung fields, and there is a 4 cm rounded area of consolidation in the left upper lobe that has an air-fluid level. Examination of her sputum reveals numerous neutrophils. Which of the following infectious agents is most likely causing her pulmonary disease?
A Staphylococcus aureus
B Aspergillus niger
C Mycobacterium tuberculosis
D Mycoplasma pneumoniae
E Adenovirus
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(A) CORRECT. Pulmonary abscesses typically have an air-fluid level. More virulent bacterial organisms such as Staphylococcus aureus are likely to cause such a complication of a bronchopneumonia.
(B) Incorrect. Fungus balls are usually firm masses that do not have central necrosis and/or cavitation.
(C) Incorrect. Although cavitation is a feature of secondary tuberculosis, air-fluid levels within the cavities are not frequent (due to the caseous nature of the necrosis).
(D) Incorrect. Infection with Mycoplasma pneumoniae typically produces patchy infiltrates, but abscess formation is not likely to occur, and the process is more interstitial with mononuclear cells.
(E) Incorrect. Adenovirus produces an interstitial pneumonitis. However, viral pneumonias may be complicated by secondary bacterial pneumonias.
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Question 24
At autopsy, a 60-year-old man is found to have a peripheral 7 cm area of golden-yellow consolidation on sectioning of the left lung. Microscopically, this area has alveoli filled with foamy macrophages. Which of the following conditions involving his lung is most likely to be responsible for this finding?
A Mycoplasma pneumoniae infection
B Cystic fibrosis
C Adenocarcinoma
D Silicosis
E Squamous cell carcinoma
F Malignant mesothelioma
G Thromboembolism
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(E) CORRECT. Most squamous cell carcinomas are located centrally and arise in bronchi, leading to obstruction of a large airway that can cause a lipid pneumonia. In this case, the breakdown of lung tissue distal to the mass yields an 'endogenous lipid pneumonia.'
(A) Incorrect. Mycoplasma infection produces an atypical pneumonia with interstitial infiltrates. Obstruction of airways is unlikely.
(B) Incorrect. The obstruction with inflammation of cystic fibrosis leads to bronchiectasis.
(C) Incorrect. Most adenocarcinomas are peripheral and do not arise within a large bronchus.
(D) Incorrect. The silicotic nodules are small (a few millimeters) and do not obstruct bronchi.
(F) Incorrect. Mesotheliomas arise in the pleura and are peripheral masses unlikely to obstruct proximal bronchi to produce a lipid pneumonia.
(G) Incorrect. Thromboemboli obstruct the pulmonary arterial system, not the bronchi.
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Question 25
A 12-year-old girl has the acute onset of dyspnea and wheezing. She coughs up a large, thick mucus plug. She has experienced similar previous episodes for the past 7 years, all of which lasted 1 to 6 hours. On physical examination her vital signs include T 37.1 C, P 109/minute, RR 27/minute, and BP 90/60 mm Hg. There are decreased breath sounds in all lung fields. A chest radiograph reveals hyperinflation but no infiltrates. Laboratory studies show WBC count of 8300/microliter with differential count of 60 segs, 3 bands, 16 lymphs, 10 monos, and 11 eosinophils. A sputum sample examined microscopically has increased numbers of eosinophils. Which of the following is the most likely diagnosis?
A Mycoplasma pneumonia infection
B Cystic fibrosis
C Hypersensitivity pneumonitis
D Bronchial asthma
E Aspiration of gastric contents
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(D) CORRECT. In an acute asthmatic episode, there can be an outpouring of mucus which, along with some dehydration, can lead to the formation of mucus plugs. The asthmatic episodes are usually initiated by a type I hypersensitivity reaction, typically with exposure to an allergen such as pollen from goldenrod or other flowering plant. Up to 10% of children may be affected to some degree.
(A) Incorrect. Mycoplasma produces an atypical pneumonia which often has a non-productive cough.
(B) Incorrect. With cystic fibrosis, there is bronchiectasis and multiple infections, so the sputum is often purulent.
(C) Incorrect. Extrinsic allergic alveolitis is produced, which is mainly an interstitial process. Extrinsic allergic alveolitis, or hypersensitivity pneumonitis, is acutely mediated by activation of complement from exposure to an allergen, but there is usually no eosinophila and the symptoms last longer than for asthma.
(E) Incorrect. Gastric contents will be liquid to semiliquid material. Aspiration is most typical for persons with neurologic impairment, though it can occur as an accident.
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