Robbin's 15: The Lung

Question 1

Pus in the pleural space is called _________, and typically complicates an existing pneumonia.

Answer 1

Pus in the pleural space is called empyema, and typically complicates an existing pneumonia.

Question 2

A 26-year-old woman with postpartum sepsis is afebrile on antibiotic therapy, but she has had worsening oxygenation over the past 3 days. Her chest radiograph shows scattered bilateral pulmonary opacifications. A ventilation-perfusion scan shows areas of mismatch. What microscopic finding is most likely to be present in her lungs?

Answer 2

Alveolar hyaline membranes She has acute lung injury with noncardiogenic pulmonary edema and development of diffuse alveolar damage (DAD), clinically known as acute respiratory distress syndrome (ARDS). Inciting sepsis, trauma, or other forms of lung injury leads to a vicious cycle of inflammation with ongoing damage, mainly through the action of neutrophils. Though ARDS may eventually proceed to fibrosis, most patients do not survive that long.

Question 3

Plexiform lesions of the lung are characteristic for _________

Answer 3

Plexiform lesions are characteristic for pulmonary hypertension.

Question 4

Destruction of respiratory bronchioles is a feature of _________.

Answer 4

Destruction of respiratory bronchioles is a feature of centrilobular emphysema.

Question 5

Dynein arms are absent or abnormal in what disease, which leads to bronchiectasis?

Answer 5

Dynein arms are absent or abnormal in Kartagener syndrome, which leads to bronchiectasis.

Question 6

A 20-year-old, previously healthy man is jogging one morning when he trips and falls to the ground. He suddenly becomes markedly short of breath. On examination in the emergency room there are no breath sounds audible over the right side of the chest. A chest radiograph shows shift of the mediastinum from right to left. A chest tube is inserted on the right side, and air rushes out. What underlying disease is most likely to have produced this complication?

Answer 6

Distal acinar emphysema Distal acinar (paraseptal) emphysema is localized, beneath pleura typically in an upper lung lobe, and may occur in an area of fibrosis or scar formation. Although the lesions are usually less than 2 cm in diameter, they are prone to rupture spontaneously or with minor trauma, leading to pneumothorax. They can be a cause for spontaneous pneumothorax in young adults. A “ball valve” effect can lead to air trapping in pleura, producing tension pneumothorax, as in this case.

Question 7

Centriacinar emphysema arises in respiratory bronchioles and is seen in what population?

Answer 7

Smokers

Question 8

What kind of emphysema involves most of the lung lobule and can be seen in all lobes; α1-antitrypsin deficiency is the most likely antecedent?

Answer 8

Panacinar (panlobular) emphysema involves most of the lung lobule and can be seen in all lobes; α1-antitrypsin deficiency is the most likely antecedent.

Question 9

What is the most likely complication of bronchiectasis?

Answer 9

Bronchiectasis results from inflammation with destruction of bronchi; hemoptysis is the most likely complication. Bronchiectasis results in airway dilation from destructive bronchial wall inflammation.

Question 10

What is an expected complication of corpulmonale?

Answer 10

Pleural effusions

Question 11

Centrilobular emphysema results from damage to the central part of the lung acinus, with dilation that primarily affects what part of the lung?

Answer 11

Centrilobular emphysema results from damage to the central part of the lung acinus, with dilation that primarily affects the respiratory bronchioles.

Question 12

A 62-year-old man is a smoker with a 10-year history of cough productive of copious mucopurulent sputum. Over the past 6 months, he has developed progressive dyspnea. Physical examination shows bilateral pedal edema and a soft but enlarged liver. A chest radiograph shows bilateral pleural effusions and a prominent right heart border. Arterial blood gas values are Po2, 60 mm Hg; Pco2, 52 mm Hg; pH, 7.30; and HCO3−, 29 mEq/L. He is intubated and placed on a ventilator, and he requires increasing amounts of oxygen. What microscopic finding is most likely to be present in the affected lungs?

Answer 12

Hypertrophy of bronchial submucosal glands Chronic bronchitis can be complicated by pulmonary hypertension and cor pulmonale. There are few characteristic microscopic features of chronic bronchitis, so it is mainly defined clinically by the presence of a persistent cough with sputum production for at least 3 months in at least 2 consecutive years.

Question 13

A 12-year-old girl has a 7-year history of coughing and wheezing and repeated attacks of difficulty breathing. The attacks are particularly common in the spring. During an episode of acute respiratory difficulty, a physical examination shows that she is afebrile. Her lungs are hyperresonant on percussion, and a chest radiograph shows increased lucency of all lung fields. Laboratory tests show an elevated serum IgE level and peripheral blood eosinophilia. A sputum sample examined microscopically also has increased numbers of eosinophils. What histologic feature is most likely to characterize the lung in her condition?

Answer 13

Remodeling of airways with smooth muscle hyperplasia Atopic asthma is a type I hypersensitivity reaction in which there are presensitized, IgE-coated mast cells in mucosal surfaces and submucosa of airways. Contact with an allergen results in degranulation of the mast cells, with both immediate release (minutes) of mediators such as histamine to promote bronchoconstriction, and delayed release (an hour or more) of leukotrienes and prostaglandins via the arachidonic acid pathway; these attract leukocytes, particularly eosinophils, and promote bronchoconstriction. The characteristic histologic changes in the bronchi, including remodeling of airways and smooth muscle hyperplasia, result from the episodes of inflammation.

Question 14

Bronchial dilation with inflammatory destruction is a feature of _________.

Answer 14

Bronchial dilation with inflammatory destruction is a feature of bronchiectasis.

Question 15

Charcot-Leyden crystals represent the breakdown products of ________.

Answer 15

The Charcot-Leyden crystals represent the breakdown products of eosinophil granules. Asthma, particularly extrinsic (atopic) asthma, is driven by a type I hypersensitivity response and is associated with an excessive TH2 and TH17 cell-mediated immune response. Genetic factors are important in the pathogenesis of atopic asthma and linkage to cytokine genes that map on 5q are strongly associated with development of asthma and other atopic allergies.

Question 16

A 19-year-old man has a history of recurrent mucoid rhinorrhea with chronic sinusitis and otitis media since childhood. He has experienced multiple bouts of pneumonia. His temperature is 37.7° C. On examination of his chest, there is tactile fremitus, rhonchi, and rales in lower lung fields. Nasal polyps are noted. A chest radiograph shows bronchial dilation with bronchial wall thickening, focal atelectasis, and areas of hyperinflation; his heart shadow appears mainly on the right. What abnormality is he most likely to have?

Answer 16

Ciliary dyskinesia He has Kartagener syndrome (sinusitis, bronchiectasis, and situs inversus associated with ciliary dyskinesia). There is an abnormality of ciliary dynein arms that diminishes the mucociliary function of the respiratory epithelium, predisposing to recurrent and chronic infections of both upper and lower respiratory tract.

Question 17

A 35-year-old woman has experienced multiple bouts of severe necrotizing pneumonia since childhood, with Haemophilus influenzae, Staphylococcus aureus, Pseudomonas aeruginosa, and Serratia marcescens cultured from her sputum. She now has a cough productive of large amounts of purulent sputum. On physical examination, there is dullness to percussion with decreased breath sounds over the right mid to lower lung fields. A chest radiograph shows areas of right lower lobe consolidation. A bronchogram shows marked dilation of right lower lobe bronchi. What mechanism is the most likely cause of her disease?

Answer 17

Recurrent inflammation with bronchial wall destruction Bronchiectasis is a chronic obstructive airway disease from irreversible dilation of bronchi that results from inflammation and destruction of bronchial walls after prolonged infections or obstruction. Serious bouts of pneumonia can predispose to bronchiectasis.

Question 18

BMPR2 is associated with development of what pathology?

Answer 18

BMPR2 is associated with development of primary pulmonary hypertension.

Question 19

Mutations in ______ are related to development of pulmonary alveolar proteinosis.

Answer 19

Mutations in GM-CSF are related to development of pulmonary alveolar proteinosis.

Question 20

A 54-year-old woman has had a mild fever with cough for a week. Her symptoms gradually improve over the next 10 days. She then begins to have increasing fever, cough, shortness of breath, and malaise. Now, on physical examination, her temperature is 37.9° C. There are inspiratory crackles on auscultation of the chest. A chest radiograph shows bilateral, patchy, small alveolar opacities. Chest CT scan shows small, scattered, ground-glass and nodular opacities. A transbronchial biopsy specimen shows polypoid plugs of loose fibrous tissue and granulation tissue filling bronchioles, along with a surrounding interstitial infiltrate of mononuclear cells. She receives a course of corticosteroid therapy, and her condition improves. What is the most likely diagnosis?

Answer 20

Cryptogenic organizing pneumonia Bronchiolitis obliterans is a feature of cryptogenic organizing pneumonia, an uncommon, nonspecific reaction to a lung injury, such as an infection or toxic exposure.

Question 21

Desquamative interstitial pneumonitis is related to what predisposition?

Answer 21

Desquamative interstitial pneumonitis (DIP) is an uncommon smoking-related interstitial disease in which monocytes gather to form intra-alveolar macrophages.

Question 22

What “pathogen” produces ferruginous bodies in the lungs?

Answer 22

Asbestos The ferruginous bodies are long, thin crystals of asbestos that have become encrusted with iron and calcium. The inflammatory reaction incited by these crystals promotes fibrogenesis and resultant pneumoconiosis.

Question 23

What is commonly seen on CXR of a patient with asbestos?

Answer 23

Diaphragmatic pleural calcified plaques The inhaled asbestos fibers become encrusted with iron and appear as the characteristic ferruginous bodies with iron stain. The firm, tan mass encasing the pleura is most likely a malignant mesothelioma. Asbestosis more commonly gives rise to pleural fibrosis and interstitial lung disease, similar to other pneumoconioses. This is seen grossly as a dense pleural plaque, which often is calcified. Asbestosis can give rise to bronchogenic carcinoma, especially in smokers.

Question 24

Upper lobe cavitation suggests what infection?

Answer 24

Upper lobe cavitation suggests secondary tuberculosis.

Question 25

A 61-year-old woman has noted increasing dyspnea and a nonproductive cough for 5 months. On physical examination, her temperature is 37.7° C. A chest radiograph shows prominent hilar lymphadenopathy with reticulonodular infiltrates bilaterally. A transbronchial biopsy is performed, and the microscopic findings include interstitial fibrosis and small, noncaseating granulomas. One granuloma contains an asteroid body in a Langhans giant cell. The medical history indicates that she smoked cigarettes for 10 years, but stopped 5 years ago. What is the most likely cause of her illness?

Answer 25

T-cell mediated response to unknown antigen The clinical and morphologic features strongly suggest sarcoidosis. This granulomatous disease has an unknown cause, but the presence of granulomas and activated T cells in the lungs indicates a delayed hypersensitivity response to some inhaled antigen. Lung involvement, occurring in about one third of cases, may be asymptomatic or may lead to restrictive lung disease. Sarcoidosis can involve multiple organs, particularly those of the mononuclear phagocyte system, especially lymph nodes.

Question 26

Diffuse alveolar damage is an acute lung injury seen in:

Answer 26

Diffuse alveolar damage is an acute lung injury seen in acute respiratory distress syndrome.

Question 27

What is farmer’s lung?

Answer 27

Farmer’s lung is a form of hypersensitivity pneumonitis caused by inhalation of actinomycete spores in moldy hay. These spores contain the antigen that incites the hypersensitivity reaction. Because type III (early) and type IV immune hypersensitivity reactions are involved, granuloma formation can occur. The disease abates when the patient is no longer exposed to the antigen. Chronic exposure can lead to more extensive interstitial lung disease.

Question 28

What is the cause of death with a saddle embolus?

Answer 28

Sudden death occurs from hypoxemia or from acute cor pulmonale with right-sided heart failure.

Question 29

Antiphospholipid antibodies pose a risk for _______.

Answer 29

Antiphospholipid antibodies pose a risk for thrombosis. Over half of persons with chronic pulmonary thromboembolism with pulmonary hypertension do not have a history of recurrent pulmonary embolism.

Question 30

The finding of pulmonary hypertension in a young individual without any known pulmonary or cardiac disease is typical for primary pulmonary hypertension. With what gene is this associated?

Answer 30

BMPR-2 - bone morphogenic receptor 2 BMPR2, a cell surface protein belonging to the TGF-β receptor superfamily, causes inhibition of vascular smooth muscle cell proliferation and favors apoptosis. In the absence of BMPR2 signaling, smooth muscle proliferation occurs, and pulmonary hypertension ensues.

Question 31

Lysyl hydroxylase is required for cross-linking collagen, and its loss gives rise to one form of _________

Answer 31

Lysyl hydroxylase is required for cross-linking collagen, and its loss gives rise to one form of Ehlers-Danlos syndrome.

Question 32

Mutation in the gene for _________ occurs in Marfan syndrome.

Answer 32

Mutation in the gene for fibrillin-1 (FBN1) occurs in Marfan syndrome.

Question 33

Goodpasture syndrome leads to renal and pulmonary lesions produced by an antibody directed against an antigen common to the basement membrane in glomerulus and alveolus. What kind of hypersensitivity reaction then ensues?

Answer 33

Type II

Question 34

The C-ANCA test (PR3) result is often positive in what disease?

Answer 34

The C-ANCA test (PR3) result is often positive in granulomatosis with polyangiitis

Question 35

A positive P-ANCA (MPO) result suggests what disease?

Answer 35

A positive P-ANCA (MPO) result suggests microscopic polyangiitis

Question 36

Name the responsible pathogen: Lobar pneumonia Productive cough with purulent sputum High percentage of neutrophils

Answer 36

Streptococcus pneumoniae

Question 37

What is the likely offending organism? A 71-year-old woman Smoker w/ COPD increasing dyspnea 3-day time course of worsening symptoms Febrile Productive cough Severe dyspnea Rales and Expiratory wheezes Neutrophilia

Answer 37

Moraxella Catarrhalis The short time course and acute inflammatory response are consistent with bacterial pneumonitis. Moraxella is the only bacterial organism listed and is in the differential diagnosis of both upper and lower respiratory infections, particularly in persons with chronic obstructive pulmonary disease (COPD), such as this woman. Moraxella is an aerobic gram-negative diplococcus that is oxidase positive. often causing sinusitis, otitis, and upper respiratory infections.

Question 38

An alcoholic aspirates and develops a lung abscess. What organisms are likely responsible and why?

Answer 38

Staphylococcus aureus and Bacteroides fragilis Bacterial organisms are most likely to produce abscesses, and the infection may be polymicrobial. The most common pathogen is Staphylococcus aureus, but anaerobes such as Bacteroides, Peptococcus, and Fusobacterium spp. also may be implicated. These anaerobes normally are found in the oral cavity and are readily aspirated. The purulent, liquefied center of the abscess can produce the radiographic appearance of an air-fluid level.

Question 39

Name the offending organism associated with these symptoms: Mild fever Nonproductive cough HA Myalgias 1 week duration CXR shows extensive bilateral patchy infiltrates Cold agglutinin titer is elevated

Answer 39

This primary atypical pneumonia is caused by Mycoplasma pneumoniae, a cell wall–deficient organism that is difficult to culture. Often, a diagnosis is made empirically. The findings are similar to those of other viral infections, and serologic testing shows the specific organism.

Question 40

An epidemiologic study shows that a highly pathogenic strain of influenza A virus with the antigenic type H5N1 that normally causes disease in birds has been increasingly found to cause influenza in humans. Unlike other strains of influenza A virus, this H5N1 virus is associated with a 60% mortality rate. The enhanced pathogenicity of this avian flu virus is primarily due to mutation in its genome that enables it to do what?

Answer 40

Enter many types of host cells H5N1 virus has much broader tissue tropism because its hemagglutinin can be cleaved by proteases present in many tissues.

Question 41

Associate neutrophilic patchy infiltrates with productive cough with what viral pneumonia infection?

Answer 41

Haemophilus influenzae

Question 42

Human metapneumovirus is seen in what population?

Answer 42

Children similar to RSV bilateral diffuse interstitial infiltrates on CXR generally self-limiting

Question 43

A CXR of a patient with RSV would show:

Answer 43

Interstitial infiltrates

Question 44

Charcot-Leyden crystals form from eosinophil granules in individuals with _______.

Answer 44

Charcot-Leyden crystals form from eosinophil granules in individuals with allergic asthma.

Question 45

The rapid plasma reagin test is used to diagnose ______

Answer 45

The rapid plasma reagin test is used to diagnose syphilis

Question 46

Anticentromere antibody is characteristic of ______

Answer 46

Anticentromere antibody is characteristic of limited scleroderma, which does not have significant pulmonary involvement, in contrast to diffuse scleroderma.

Question 47

What is the characteristic lung presentation of an infection with legionella?

Answer 47

Legionella is likely to produce a widespread bronchopneumonia with alveolar neutrophilic exudates.

Question 48

How does infection with Nocardia present?

Answer 48

Nocardiosis of the lung appears mainly as chronic abscessing inflammation.

Question 49

What is the likely offending organism producing these symptoms: Immunocomprimised individual (ie chemo); Halo sign: chest CT scan shows multiple 1- to 4-cm nodular densities w/ surrounding areas of ground-glass infiltrate; branching septate hyphae found in sputum from broncheolar lavage

Answer 49

Aspergillus fumigatus Immunocompromised patients with neutropenia may develop invasive aspergillosis. Other patterns include allergic bronchopulmonary aspergillosis in persons with asthma and an aspergilloma, or fungus ball, colonizing a cavitary lesion of tuberculosis or bronchiectasis.

Question 50

Within the airspace are multiple large cells with prominent purple intranuclear inclusions, indicative of what infection?

Answer 50

CMV immunocomprimised marked interstitial pneumonitis

Question 51

Gomori methenamine silver is used to identify what organism that has a predilection for the immunocomprimised?

Answer 51

Pneumocystis jiroveci Often associated with AIDS patients

Question 52

What lung cancer is most likely to produce paraneoplastic hypercalcemia?

Answer 52

Squamous cell carcinoma strong association with smoking. These tumors also can undergo central necrosis—hence a cavity may form. Localized squamous cell carcinomas, in contrast to small cell carcinomas, may be cured by surgery.

Question 53

Name the kind of cancer: Peripheral subpleural mass Nonsmoker Glandular appearance on H&E

Answer 53

Adenocarcinoma Cancers that arise in nonsmokers are pathogenetically distinct from those that occur in smokers. They may have either EGFR mutations or KRAS mutations. Most are adenocarcinomas. Twenty-five percent of lung cancers worldwide occur in nonsmokers. Primary adenocarcinomas in the lung tend to be small, peripheral masses that are amenable to surgical excision and have a better overall prognosis than other forms of lung cancer.

Question 54

What is the prognosis for small cell lung carcinoma?

Answer 54

Small cell carcinomas are aggressive neuroendocrine tumors that tend to metastasize early. Even when they appear to be small and localized, they are not or will not remain so. Surgery is not an option for these patients. They are treated as if they have systemic disease; some chemotherapy protocols afford benefit for 1 year or more, but cure is uncommon.

Question 55

The most common primary lung cancers for smokers to develop are:

Answer 55

Small cell - invasive perihilar mass, poorly differntiated Squamous cell

Question 56

Small cell carcinomas are frequently associated with what other symptoms?

Answer 56

Paraneoplastic syndromes such as Cushing syndrome and SIADH Cushing syndrome is a paraneoplastic syndrome resulting from ectopic corticotrophin production (most often from a pulmonary small cell carcinoma), which drives the adrenal cortices to produce excess cortisol. syndrome of inappropriate secretion of antidiuretic hormone (SIADH), marked by free water retention with hyponatremia

Question 57

Large cell carcinoma is usually well-defined and appears as:

Answer 57

large and pleomorphic and form sheets tends to be peripheral

Question 58

Adenocarcinoma in situ (AIS) presents often as:

Answer 58

Single lesion Well differentiated Mistaken for pneumonia initially Often peripheral

Question 59

Oat cell cancers are central tumors and are strongly associated with:

Answer 59

Smoking

Question 60

What is the diagnosis: Gross appearance is Firm, glistening, bluish white cut surface; Single lesion in lung;

Answer 60

Hamartomas are uncommon but benign peripheral lesions of the lung. They are composed of benign-appearing epithelial cells and connective tissue, typically with a large component of cartilage. They are included in the differential diagnosis of a “coin lesion” that also includes carcinoma and granuloma.

Question 61

Non smokers who develop hemoptysis and bronchial obstruction (increasing cough) may have what benign lung lesion?

Answer 61

Carcinoid tumor Most pulmonary carcinoids are central obstructing masses involving a large to medium-sized bronchus. These neuroendocrine tumors have unpredictable behavior, but many are localized, resectable, and follow a benign course.

Question 62

Chylothorax is a potential complication of what neoplastic process, resulting in widened mediastinum, dyspnea and thoracentesis that shows high protein content; microscopy shows many lymphocytes and fat globules?

Answer 62

Non-Hodgkin lymphoma with lymphatic obstruction Disruption of the thoracic duct in the posterior chest is most likely to cause chylothorax, and malignant neoplasms, such as a non-Hodgkin lymphoma, are most likely to do this.