Question 11
A 41-year-old man with a 6 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 13.8 g/dL, Hct 41.4%, MCV 91 fL, and platelet count 317,000/microliter. His CD4 lymphocyte count is 79/microliter. Cryptosporidium parvum organisms are found in a stool specimen. A bronchoalveolar lavage 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 Multiple cysts with GMS stain
D Hemosiderin-laden macrophages
E Short gram positive rods
--------------------------------------------------
(C) CORRECT. He is most likely to have Pneumocystis carinii (jirovecii) pneumonia in association with the acquired immunodeficiency syndrome. PCP has an exudate composed of the Pneumocystis cysts and trophozoites with little accompanying inflammation. The clinical findings in this case are typical as well.
(A) Incorrect. Mycobacterial infection is unlikely in this setting, for there is still typically caseous necrosis and even poorly formed granulomas in an immunocompromised person with M. tuberculosis. M. avium-complex is less likely to produce florid pulmonary disease.
(B) Incorrect. Aspergillus often produces a fungus ball, or a defined mass, rather than infiltrates. It does not produce an acellular exudate.
(D) Incorrect. Pulmonary hemorrhage in the setting of AIDS is not common. The clinical features suggest an acute infection.
(E) Incorrect. This suggests listeriosis, a disease that can sometimes be seen in immunocompromised persons, but it is not common, and it produces focal abscesses or small granulomas, not foamy exudate.
---------------------------------------------------------
Question 12
A 60-year-old man has a 90 pack year history of smoking. For the past 5 years, he has had a cough productive of copious amounts of mucoid sputum for months at a time. He has had episodes of pneumonia with Streptococcus pneumoniae and E. coli cultured. His last episode of pneumonia is complicated by septicemia and brain abscess and he dies. At autopsy, his bronchi microscopically demonstrate mucus gland hypertrophy. Which of the following conditions is most likely to explain his clinical course?
A Squamous cell carcinoma
B Congestive heart failure
C Chronic bronchitis
D Bronchial asthma
E Centrilobular emphysema
F Panlobular emphysema
G Bronchiectasis
-------------------------------------------------------
(C) CORRECT. Chronic bronchitis is defined clinically as a person who has persistent cough with sputum production for at least 3 months in at least 2 consecutive years. Air pollution and smoking are key causes for chronic bronchitis.
(A) Incorrect. Though lung cancers are more common in persons who smoke, his findings are not explained by a mass lesion, and his symptoms have persisted for years.
(B) Incorrect. Congestive heart failure will produce pulmonary edema, if it is primarily left heart failure. If severe, there can be 'rusty' colored sputum.
(D) Incorrect. Attacks of asthma are quite intermittent, and there is usually not a great amount of sputum production.
(E) Incorrect. As a smoker, he is at risk for development of emphysema, but this does not explain his sputum production. Sometimes, smokers have elements of both emphysema and chronic bronchitis.
(F) Incorrect. Smoking can lead to severe bullous emphysema that can eventually involve a large amount of lung tissue, but a true panlobular pattern of emphysema is more typical for condtions such as alpha-1-antitrypsin deficiency.
(G) Incorrect. Bronchiectasis is not a typically complication of smoking.
------------------------------------------------------
Question 13
A 66-year-old man has had increasing dyspnea for the past year. He is a smoker. He is retired from the construction business. There are some rales auscultated in both lungs on physical examination. A chest radiograph reveals bilateral diaphragmatic pleural plaques with focal calcification as well as diffuse interstitial lung disease. A sputum cytology shows no atypical cells. Pulmonary function studies reveal a low FVC and a normal FEV1/FVC ratio. These findings are most likely to suggest prior exposure to which of the following environmental agents?
A Cotton fibers
B Silica dust
C Fumes with iron particles
D Asbestos crystals
E Beryllium
F Mold spores
------------------------------------------------
(D) CORRECT. These findings are classic for exposure to asbestos. Pleural plaques are more frequent in this condition than in other pneumonconioses, particularly with calcification. Asbestosis is a form of pneumoconiosis that can lead to restrictive lung disease. In smokers, there is an increased risk for development of bronchogenic carcinomas.
(A) Incorrect. Byssinosis produces an asthma-like disease.
(B) Incorrect. Silicosis more typically produces a pattern of silicotic nodules in lung. Inorganic dusts often produce interstitial fibrosis.
(C) Incorrect. Increased iron in the lung is an uncommon form of pneumoconiosis. It is more likely to occur with hemochromatosis with iron overload.
(E) Incorrect. Berylliosis produces sarcoid-like granulomatous disease chronically, and an acute pneumonitis acutely.
(F) Incorrect. Mold spores produce an extrinsic allergic alveolitis, which rarely is severe enough to produce chronic lung disease. It does not produce pleural plaques.
----------------------------------------------
Question 14
A 58-year-old man has been a smoker for 40 years. He has had an 8 kg weight loss over the past 6 months accompanied by a chronic cough and malaise. He reports no fever, nausea, or vomiting. He had a recent episode of hemoptysis. A chest radiograph reveals a 5 cm diameter mass in the medial left upper lobe. Bronchoscopy reveals a mass lesion involving the left superior segmental bronchus. Which of the following cytologic findings is most likely to be present in this man?
A Cysts staining with GMS in a bronchoalveolar lavage fluid
B Pleural fluid with atypical mesothelial cells
C Epthelioid cells with necrotic debris in a fine needle aspirate
D Malignant appearing squamous cells in sputum
E Intranuclear inclusions in large epithelial cells in bronchoalveolar lavage fluid
-------------------------------------------
(D) CORRECT. The large central mass is consistent with a squamous cell carcinoma, which is seen mainly in smokers.
(A) Incorrect. Pneumocystis carinii (jirovecii) pneumonia is a diffuse process and occurs in immunocompromised patients. Hemoptysis does not occur.
(B) Incorrect. Mesothelioma is rare; it is characterized by a bulky pleural mass in a person with prior asbestos exposure.
(C) Incorrect. Granulomatous inflammation is typical for mycobacterial and fungal infections; though a solitary granuloma may be present, it is usually not larger than 2 to 3 cm in size.
(E) Incorrect. Cytomegalovirus infections occur in immunocompromised patients. No mass is present.
---------------------------------------------
Question 15
A 44-year-old man with a history of chronic alcohol abuse has lost 6 kg in the past five months. He has had a cough with hemoptysis along with pleuritic chest pain for the past 2 weeks. On physical examination his temperature is 37.5 C. A chest radiograph reveals a bilateral reticulonodular pattern of infiltrates. A transbronchial biopsy is performed and on microscopic examination shows epithelioid cells with necrotic debris. Laboratory studies show a WBC count of 5890/microliter with 78% granulocytes, 15% lymphocytes, and 7% monocytes. Which of the following additional histologic findings is most likely to be present on his biopsy?
A Branching, septated hyphae
B Pleomorphic cells with dark, angular nuclei
C Clusters of small RBC-sized cysts staining with GMS
D Small, rounded hyperchromatic cells with a high N/C ratio
E Acid fast bacilli
-----------------------------------------------
(E) CORRECT. The hemoptysis suggests that the granulomas have eroded enough parenchyma and involved a bronchus. A granulomatous reaction is typical for Mycobacterium tuberculosis.
(A) Incorrect. Aspergillus infection is not common. It is more likely to produce a fungus ball. Persons who are neutropenic are at greatest risk. The inflammatory reaction could vary from acute to mixed to granulomatous.
(B) Incorrect. A squamous cell carcinoma is usually a central mass lesion. It is unlikely that epithelioid cells would appear on biopsy.
(C) Incorrect. PCP in rare cases has a granulomatous pattern, but the granulomas would be small and unlikely to lead to hemoptysis.
(D) Incorrect. Small cell anaplastic carcinomas are centrally located. They are unlikely to be found with epithelioid cells.
--------------------------------------------
No comments:
Post a Comment