Question 175
A 54-year-old male with a 5 year history of increasing shortness of breath presents to his family physician at his wife’s insistence for further testing. He has a 50 pack-year smoking history. Physical examination reveals a barrel chest, and auscultation of his chest reveals decreased breath sounds and occasional wheezes, but no crackles. A chest x-ray reveals a flattened diaphragm and increase lucency of the lung fields. Which of the following mechanisms played the greatest role in the primary development of his disease process?
A. Protease-anti-protease imbalance
B. Recurrent infections
C. Airway hypersensitivity to nicotine
D. Allergen enhancement of tissue fibrosis
E. Neoplastic infiltration of pulmonary parenchyma
Answer for Question 175
Answer: A (Protease-anti-protease imbalance).
Explanation: The history (54-year-old male with a >40 pack-year smoking history presenting with chronic dyspnea), physical examination (barrel chest, decreased breath sounds and wheezing), and x-ray (flattened diaphragm and increased lucency of the lung fields) are consistent with emphysema. Oxidative stress, inflammation, and an imbalance of proteases-anti-proteases are the three main mechanisms by which emphysema develops. Individuals with emphysema are at increased risk for pneumonia, and pneumonia contributes to exacerbations of the disease, but are not as important in the primary development of the disease process as is the protease-anti-protease imbalance. Airway hypersensitivity, important in asthma, is not important in the primary development of emphysema. Fibrosis is not a significant component of emphysema and neoplastic proliferation would more likely present as a restrictive lung disease, or, bronchiectasis, if there was airway obstruction, but is not the primary mechanism for the development of emphysema.
Question 176
A 35-year-old male with a 2 year history of increasing shortness of breath presents to his family physician for evaluation. He has a 15 pack-year smoking history. Auscultation of his chest reveals decreased breath sounds and occasional crackles. Pulmonary function testing reveals a decreased FEV1/FVC ratio. Of the following, which set of parameters best describes his disease process involvement of the lungs?
Answer for Question 176
Answer: D (Panacinar and lower lobes)
Explanation: The clinical presentation (chronic dyspnea associated with decreased breath sounds and occasional crackles) combined with the PFTs (decreased FEV1/FVC ratio) is consistent with emphysema. Given his young age and mild smoking history, he most likely has α1-antitrypsin deficiency, which causes panacinar emphysema and affects more commonly the lower lobes, whereas emphysema due to smoking causes centriacinar emphysema and affects the upper lobes.
Question 177
A 32-year-old male with a 1 year history of increasing shortness of breath presents to his family physician for evaluation. He has a 10 pack-year smoking history. Auscultation of his chest reveals decreased breath sounds and occasional crackles. Pulmonary function testing reveals a decreased FEV1/FVC ratio. Of the following conditions, which is this patient at greatest risk for?
A. Early-onset degenerative aortic stenosis
B. Amyloidosis of the heart
C. Adenocarcinoma of the gallbladder
D. Hepatocellular carcinoma
E. Glioblastoma multiforme
Answer for Question 177
Answer: D (Hepatocellular carcinoma)
Explanation: The clinical presentation (chronic dyspnea associated with decreased breath sounds and occasional crackles) combined with the PFTs (decreased FEV1/FVC ratio) is consistent with emphysema. Given his young age and mild smoking history, he most likely has α1-antitrypsin deficiency. Patients with α1-antitrypsin deficiency are at risk for emphysema and, often, cirrhosis of the liver. Individuals with cirrhosis of the liver are at risk for the development of hepatocellular carcinoma. α1-antitrypsin deficiency is not commonly associated with the other conditions listed.
Question 178
A 19-year-old female college student is being seen in the emergency room for an episode of severe dyspnea. In the last 5 years, she has had to go to the emergency room 4 times for a similar episode. Vital signs include blood pressure of 123/80 mmHg, heart rate of 112 bpm, and respiratory rate of 30 bpm. During inspiration, her systolic blood pressure decreases by 15 mmHg. Physical examination reveals her to be in acute distress. Auscultation of the chest reveals wheezes. The underlying mechanism of her disease process is which of the following?
A. Type I hypersensitivity reaction
B. Type II hypersensitivity reaction
C. Type III hypersensitivity reaction
D. Type IV hypersensitivity reaction
Answer for Question 178
Answer: A (Type I hypersensitivity reaction)
Explanation: The clinical presentation (acute onset of severe dyspnea in a young adult, with history of previous such episodes in the past, and with wheezing, tachypnea, tachycardia, and pulsus paradoxus (the decrease in systolic blood pressure with inspiration) is consistent with asthma. The underlying mechanism of asthma is a type I hypersensitivity reaction.
Question 179
A 13-year-old female is brought to the emergency room by her parents as she has developed severe dyspnea, and they can see her using the muscles in her neck to help her breath. Her mother has a history of developing a rash after working outside on occasions. Her vital signs include blood pressure of 119/78 mmHg, heart rate of 115 bpm, and respiratory rate of 32 bpm. During inspiration, her systolic blood pressure decreases by 16 mmHg. Physical examination reveals her to be in acute distress. Auscultation of the chest reveals wheezes. Of the following, which histologic change is most likely present in the lungs?
A. Loss of pulmonary parenchyma
B. Numerous granulomas
C. Infiltrates of neutrophils
D. Infiltrates of plasma cells
E. Infiltrates of eosinophils
Answer for Question 179
Answer: E (Infiltrates of eosinophils)
Explanation: The clinical presentation (acute onset of severe dyspnea in child, and with wheezing, tachypnea, tachycardia, and pulsus paradoxus) is consistent with asthma. Histologic changes in asthma include hypertrophy of the smooth muscle of the airways, sub-basement membrane fibrosis making the basement membrane appear thick, mucous gland hyperplasia, and infiltrates of eosinophils. Curschmann spirals (mucous casts of the airways with shed epithelium) and Charcot-Leyden crystals can also be identified. Given that this is her first presentation, the other histologic features of asthma would probably not be well-developed.