Chest

Question 1

x bronchioles are less than 2 mm in diameter.

Beyond the x bronchiole is the acinus, a roughly spherical structure with a diameter of about 7 mm. An acinus is composed of a x x (which gives off several alveoli from its sides), x ducts, and x sacs, the blind ends of the respiratory passages, whose walls are formed entirely of x, the site of gas exchange.

A cluster of three to five x bronchioles, each with its appended acinus, is referred to as the pulmonary lobule.

Answer 1

Terminal bronchioles, which are less than 2 mm in diameter.

Beyond the terminal bronchiole is the acinus, a roughly spherical structure with a diameter of about 7 mm. An acinus is composed of a respiratory bronchiole (which gives off several alveoli from its sides), alveolar ducts, and alveolar sacs, the blind ends of the respiratory passages, whose walls are formed entirely of alveoli, the site of gas exchange.

A cluster of three to five terminal bronchioles, each with its appended acinus, is referred to as the pulmonary lobule.

Question 2

Except for the x vocal cords, which are covered by x, the entire respiratory tree, including the larynx, trachea, and bronchioles, is normally lined mainly by x and a smaller population of non-ciliated cells called club cells that secrete a number of protective substances into the airway.

Answer 2

Except for the true vocal cords, which are covered by stratified squamous epithelium, the entire respiratory tree, including the larynx, trachea, and bronchioles, is normally lined mainly by tall, columnar, pseudostratified, ciliated epithelial cells and a smaller population of non-ciliated cells called club cells that secrete a number of protective substances into the airway.

Question 3

Resp/lung

Alveolar epithelium, a continuous layer of two cell types: x, covering 95% of the alveolar surface, and x.

x cells synthesize surfactant (which forms a very thin layer over the alveolar cell membranes) and are involved in the repair of alveolar damage through their ability to proliferate and give rise to type I cells.

Answer 3

Alveolar epithelium, a continuous layer of two cell types: flat, plate-like type I pneumocytes, covering 95% of the alveolar surface, and rounded type II pneumocytes.

Type II cells synthesize surfactant (which forms a very thin layer over the alveolar cell membranes) and are involved in the repair of alveolar damage through their ability to proliferate and give rise to type I cells.

The alveolar walls are perforated by numerous pores of Kohn, which permit the passage of bacteria and exudate between adjacent alveol

Question 4

A bronchogenic cyst is x connected to the tracheobronchial tree.

Answer 4

rarely

Question 5

Pulmonary sequestration is a discrete area of lung tissue that (1) x (2) x

Describe two different types

Answer 5

Pulmonary sequestration is a discrete area of lung tissue that
(1) is not connected to the airways and
(2) has an abnormal blood supply arising from the aorta or its branches.

Extralobar sequestration is external to the lung and most commonly presents in infants as a mass lesion. Less common.
Venous drainage most commonly through the systemic veins into the right atrium (but is variable)
separated from any surrounding lung by its own pleura

Intralobar sequestration occurs within the lung. More common 85%. It usually presents in older children, often due to recurrent localized infections or bronchiectasis.
Venous drainage commonly occurs via the pulmonary veins but can occur through the azygos-hemiazygos system, portal vein, right atrium or inferior vena cava
closely connected to the adjacent normal lung and do not have a separate pleura

Question 6

Describe 3 types of atelectasis

Answer 6

• Resorption atelectasis stems from obstruction of an airway. Over time, air is resorbed from distal alveoli, which collapse. Since lung volume is diminished, the mediastinum shifts toward the atelectatic lung. Airway obstruction is most often caused by excessive secretions (e.g., mucus plugs) or exudates within smaller bronchi, as may occur in bronchial asthma, chronic bronchitis, bronchiectasis, and postoperative states. Aspiration of foreign bodies and intrabronchial tumors may also lead to airway obstruction and atelectasis.
• Compression atelectasis results whenever significant volumes of fluid (transudate, exudate, or blood), tumor, or air (pneumothorax) accumulate within the pleural cavity. With compression atelectasis, the mediastinum shifts away from the affected lung.
• Contraction atelectasis occurs when focal or generalized pulmonary or pleural fibrosis prevents full lung expansion.

Question 7

Pulmonary edema can result from x or x

x pulmonary edema is caused by increased x pressure and occurs most commonly in x

x pulmonary edema is caused by x.

Answer 7

Pulmonary edema (excessive interstitial fluid in the alveoli) can result from hemodynamic disturbances (cardiogenic pulmonary edema) or increased capillary permeability due to microvascular injury (non-cardiogenic pulmonary edema)

Hemodynamic pulmonary edema is caused by increased hydrostatic pressure and occurs most commonly in leftsided congestive heart failure.

Edema Caused by Microvascular (Alveolar) Injury.
Non-cardiogenic pulmonary edema is caused by injury of the alveolar septa. Primary injury to the vascular endothelium or damage to alveolar epithelial cells (with secondary microvascular injury) produces an inflammatory exudate that leaks into the interstitial space and, in more severe cases, into the alveoli. Injury-related alveolar edema is an important feature of a serious and often fatal condition, acute respiratory distress syndrome

Question 8

Classification and Causes of Pulmonary Edema

Answer 8

Question 9

Conditions Associated With Development of Acute Respiratory Distress Syndrome

Answer 9

Question 10

Acute lung injury (ALI) is characterized by x.

Acute respiratory distress syndrome (ARDS) is x.

Both ARDS and ALI are associated with x

Answer 10

Acute lung injury (ALI) is characterized by the abrupt onset of hypoxemia and bilateral pulmonary edema in the absence of cardiac failure (non-cardiogenic pulmonary edema). Acute respiratory distress syndrome (ARDS) is a manifestation of severe ALI. Both ARDS and ALI are associated with inflammation-associated increases in pulmonary vascular permeability, edema, and epithelial cell death. The histologic manifestation of these diseases is diffuse alveolar damage.

ALI is a well-recognized complication of diverse conditions including both pulmonary and systemic disorders. In many cases, several predisposing conditions are present (e.g., shock, oxygen therapy, and sepsis). In other uncommon instances, ALI appears acutely in the absence of known triggers and follows a rapidly progressive clinical course, a condition known as acute interstitial pneumonia.

• ARDS is a clinical syndrome of progressive respiratory insufficiency caused by diffuse alveolar damage in the setting of sepsis, severe trauma, or diffuse pulmonary infection.
• Damage to endothelial and alveolar epithelial cells and secondary inflammation are the key initiating events and the basis of lung damage.
• The characteristic histologic finding is hyaline membranes lining alveolar walls, accompanied by edema, scattered neutrophils and macrophages, and epithelial necrosis.

Question 11

Obstructive lung diseases are characterized by x

Answer 11

Obstructive lung diseases are characterized by an increase in resistance to airflow due to diffuse airway disease, which may affect any level of the respiratory tract.

Question 12

An FEV1/FVC ratio of less than x generally indicates x disease.

By contrast, x diseases are associated with x decreases in both total lung capacity and FEV1 , such that the FEV1/FVC ratio x.

Answer 12

An FEV1/FVC ratio of less than 0.7 generally indicates obstructive disease. Expiratory airflow obstruction may be caused by a variety of conditions (Table 15.3), each with characteristic pathologic changes and different mechanisms of airflow obstruction. As discussed later, however, the divisions between these entities are not “clean,” and many patients have diseases with overlapping features. By contrast, restrictive diseases are associated with proportionate decreases in both total lung capacity and FEV1 , such that the FEV1/FVC ratio remains normal.

Question 13

Restrictive defects occur in two broad kinds of conditions: (1) x and (2) x

Answer 13

Restrictive defects occur in two broad kinds of conditions: (1) chest wall disorders (e.g., severe obesity, pleural diseases, kyphoscoliosis, and neuromuscular diseases such as poliomyelitis) and (2) chronic interstitial and infiltrative diseases, such as pneumoconioses and interstitial fibrosis.

Question 14

The Spectrum of Chronic Obstructive Pulmonary Disease

Answer 14

Question 15

Emphysema is defined by x

Emphysema is subdivided into four major types:

Differences between first two types:

Answer 15

Emphysema is defined by irreversible enlargement of the airspaces distal to the terminal bronchiole, accompanied by destruction of their walls.

Emphysema is subdivided into four major types: (1) centriacinar, (2) panacinar, (3) paraseptal, and (4) irregular

Centriacinar (centrilobular) emphysema. Centriacinar
emphysema is the most common form, constituting more than 95% of clinically significant cases. It occurs pre-dominantly in heavy smokers with COPD. In this type of emphysema the central or proximal parts of the acini, formed by respiratory bronchioles, are affected, whereas distal alveoli are spared

Panacinar (panlobular) emphysema. Panacinar emphysema is associated with α1-antitrypsin deficiency (Chapter 18) and is exacerbated by smoking. In this type the acini are uniformly enlarged from the level of the respiratory bronchiole to the terminal blind alveoli. In contrast to centriacinar emphysema, panacinar emphysema tends to occur more commonly in the lower zones and in the anterior margins of the lung, and it is usually most severe at the bases

Distal acinar (paraseptal) emphysema. Distal acinar emphysema probably underlies many cases of spontaneous pneumothorax in young adults. In this type the proximal portion of the acinus is normal, and the distal part is predominantly involved. The emphysema is more striking adjacent to the pleura, along the lobular connective tissue septa, and at the margins of the lobules. It occurs adjacent to areas of fibrosis, scarring, or atelectasis and is usually more severe in the upper half of the lungs.

Question 16

Chronic bronchitis is defined clinically as x

Several factors contribute to its pathogenesis.

Answer 16

Chronic bronchitis is defined clinically as persistent cough with sputum production for at least 3 months in at least 2 consecutive years in the absence of any other identifiable cause.

Mucus hypersecretion: The basis for mucus hypersecretion is incompletely understood, but it appears to involve inflammatory mediators such as histamine and IL-13. With time, there is also a marked increase in goblet cells in small airways

Acquired cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. There is substantial evidence that smoking leads to acquired CFTR dysfunction, which in turn causes the secretion of abnormal, dehydrated mucus that exacerbates the severity of chronic bronchitis.

Inflammation. Inhalants that induce chronic bronchitis cause cellular damage, eliciting both acute and chronic inflammatory responses involving neutrophils, lymphocytes, and macrophages. Long-standing inflammation and accompanying fibrosis involving small airways (small bronchi and bronchioles, less than 2 to 3 mm in diameter) can also lead to chronic airway obstruction.

Infection. Infection does not initiate chronic bronchitis, but is probably significant in maintaining it and may be critical in producing acute exacerbations.

Question 17

Chronic bronchitis

The most striking change is an increase in the size of the x.

This increase can be assessed by the ratio of the thickness of the x gland layer to the thickness of the wall between the epithelium and the cartilage (x index).

The x index (normally x) is increased in chronic bronchitis, usually in proportion to the severity and duration of the disease.

The mucus plugging, inflammation, and fibrosis may lead to marked narrowing of bronchioles, and in the most severe cases, there may be obliteration of lumen due to fibrosis (x).

Answer 17

The most striking change is an increase in the size of the mucous glands.

This increase can be assessed by the ratio of the thickness of the mucous gland layer to the thickness of the wall between the epithelium and the cartilage (Reid index).

The Reid index (normally 0.4) is increased in chronic bronchitis, usually in proportion to the severity and duration of the disease.

The mucus plugging, inflammation, and fibrosis may lead to marked narrowing of bronchioles, and in the most severe cases, there may be obliteration of lumen due to fibrosis (bronchiolitis obliterans). The bronchial epithelium may also exhibit squamous metaplasia and dysplasia due to the irritating and mutagenic effects of substances in tobacco smoke.

Question 18

Predominant Features of Emphysema and Chronic Bronchitis

Answer 18

Question 19

Z allele, a genotype associated with very low serum levels of x.

More than x% of ZZ individuals develop symptomatic x emphysema, which occurs at an earlier age and is of greater severity if the individual smokes.

Answer 19

α1 -antitrypsin.

More than 80% of ZZ individuals develop symptomatic panacinar emphysema, which occurs at an earlier age and is of greater severity if the individual smokes.

Question 20

Asthma is a heterogeneous disease, usually characterized by x

Atopic asthma, the most common form of the disease, is caused by a x response to environmental allergens in genetically predisposed individuals.

Answer 20

Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation and variable expiratory airflow obstruction that produces symptoms such as wheezing, shortness of breath, chest tightness, and cough, which vary over time and in intensity.

**characterized by reversible bronchoconstriction caused by airway hyperresponsiveness to a variety of stimuli.

Atopic asthma, the most common form of the disease, is caused by a Th2-mediated IgE response to environmental allergens in genetically predisposed individuals.

Question 21

A characteristic finding in sputum or bronchoalveolar lavage specimens of patients with atopic asthma is x spirals, which may result from extrusion of mucus plugs from subepithelial mucous gland ducts or bronchioles.

Also present are numerous eosinophils and x crystals composed of the eosinophil-derived protein galectin-10.

Answer 21

Curschmann spirals
Charcot-Leyden crystals

Question 22

Bronchiectasis is a disorder in which x leads to x

Answer 22

Bronchiectasis is a disorder in which destruction of smooth muscle and elastic tissue by inflammation stemming from persistent or severe infections leads to permanent dilation of bronchi and bronchioles.

Question 23

x occurs in patients with x or x and frequently leads to the development of bronchiectasis.

It is a hyperimmune response to the fungus x

Answer 23

Allergic bronchopulmonary aspergillosis occurs in patients with asthma or cystic fibrosis and frequently leads to the development of bronchiectasis.

It is a hyperimmune response to the fungus Aspergillus fumigatus.

Question 24

Idiopathic pulmonary fibrosis (IPF) refers to a clinicopathologic syndrome marked by x

Answer 24

progressive interstitial pulmonary fibrosis and respiratory failure.

Question 25

Implicated factors for Idiopathic pulmonary fibrosis (IPF)

Answer 25

Most important among these is cigarette smoking, which increases the risk of IPF several- fold. IPF incidence is also increased in individuals who are exposed to air pollution, microaspiration, metal fumes, and wood dust, or who work in certain occupations, including farming, hairdressing, and stone polishing. Age >50 Genetics

Question 26

Nonspecific Interstitial Pneumonia patients have a x prognosis than patients with UIP.

Answer 26

Nonspecific Interstitial Pneumonia patients have a much better prognosis than patients with UIP. Nonspecific interstitial pneumonia is most often associated with connective tissue disease but may also be idiopathic

Question 27

Cryptogenic organizing pneumonia is most often seen as a response to x. It has been associated with x.

Answer 27

Cryptogenic organizing pneumonia is most often seen as a response to infection or inflammatory injury of the lungs. It has been associated with viral and bacterial pneumonias, inhaled toxins, drugs, connective tissue disease, and graftversus-host disease in hematopoietic stem cell transplant recipients. Patients present with cough and dyspnea and have patchy subpleural or peribronchial areas of airspace consolidation radiographically. Histologically, it is characterized by the presence of polypoid plugs of loose organizing connective tissue (Masson bodies) within alveolar ducts, alveoli, and often bronchioles. There is no interstitial fibrosis or honeycomb lung. Some patients recover spontaneously, but most need treatment with oral steroids for 6 months or longer for complete recovery. The long-term prognosis is dependent on the underlying disorder

Question 28

Pulmonary Involvement in Autoimmune Diseases. Name ...

Answer 28

Rheumatoid arthritis is associated with pulmonary involvement in 30% to 40% of patients as (1) chronic pleuritis, with or without effusion; (2) diffuse interstitial pneumonitis and fibrosis; (3) intrapulmonary rheumatoid nodules; (4) follicular bronchiolitis; or (5) pulmonary hypertension. When lung disease occurs in the setting of rheumatoid arthritis and a pneumoconiosis, it is referred to as Caplan syndrome. * Systemic sclerosis (scleroderma) is associated with diffuse interstitial fibrosis (nonspecific interstitial pattern more common than usual interstitial pattern) and pleural involvement. * Lupus erythematosus may cause patchy, transient parenchymal infiltrates or occasionally severe lupus pneumonitis, as well as pleuritis and pleural effusions. Pulmonary involvement in these diseases has a variable prognosis that is determined by the extent and histologic pattern of involvement.

Question 29

When lung disease occurs in the setting of rheumatoid arthritis and a pneumoconiosis, it is referred to as x

Answer 29

Caplan syndrome

Question 30

Lung Diseases Caused by Air Pollutants

Answer 30

Question 31

Coal workers’ pneumoconiosis is lung disease caused by x

Answer 31

inhalation of coal particles and other admixed forms of dust. Coal workers may also develop emphysema and chronic bronchitis independent of smoking.

Question 32

x is the most innocuous coal-induced pulmonary lesion in coal miners and is also seen to some degree in urban dwellers and tobacco smokers.

Answer 32

Anthracosis is the most innocuous coal-induced pulmonary lesion in coal miners and is also seen to some degree in urban dwellers and tobacco smokers. Inhaled carbon pigment is engulfed by alveolar or interstitial macrophages, which accumulate in the connective tissue adjacent to the lymphatics and in organized lymphoid tissue adjacent to the bronchi or in the lung hilus.

Question 33

Simple coal workers’ pneumoconiosis is characterized by coal macules (1 to 2 mm in diameter) and somewhat larger coal nodules. ?lobar predominance In due course dilation of adjacent alveoli occurs, sometimes giving rise to x

Answer 33

Although these lesions are scattered throughout the lung, the upper lobes and upper zones of the lower lobes are more heavily involved In due course dilation of adjacent alveoli occurs, sometimes giving rise to centrilobular emphysema.

Question 34

Coal workers’ pneumoconiosis ?% develop progressive massive fibrosis develops, leading to increasing pulmonary dysfunction, pulmonary hypertension, and cor pulmonale. ? coal workers’ pneumoconiosis increases susceptibility to tuberculosis or predispose to cancer in the absence of smoking.

Answer 34

10% Once progressive massive fibrosis develops, it may continue to worsen even if further exposure to dust is prevented. No increase in risk of TB or cancer in the absence of smoking

Question 35

Silicosis is a common lung disease caused by inhalation of proinflammatory crystalline x

Answer 35

Silicon dioxide (silica). Currently, silicosis is the most prevalent chronic occupational disease in the world. Crystalline silica (e.g., quartz) is the usual culprit.

Question 36

Silicosis is characterized grossly in its early stages by x (location)

Answer 36

Silicosis is characterized grossly in its early stages by tiny, barely palpable, discrete pale to blackened (if coal dust is also present) nodules in the hilar lymph nodes and upper zones of the lungs. Sometimes, thin sheets of calcification occur in the lymph nodes and are seen radiographically as eggshell calcification (i.e., calcium surrounding a zone lacking calcification).

Question 37

Onset of silicosis

Answer 37

The onset of silicosis may be slow and insidious (10 to 30 years after exposure; this is most common), accelerated (within 10 years of exposure), or rapid (weeks or months after intense exposure to fine dust high in silica; this is rare) The disease may continue to worsen even if the patient is no longer exposed.

Question 38

?which pneumoconiosis is associated with an increased susceptibility to tuberculosis and a twofold increased risk of lung cancer.

Answer 38

Silicosis

Question 39

Asbestos is a family of proinflammatory crystalline hydrated silicates that are associated with x and x

Answer 39

pulmonary fibrosis and various forms of cancer.

Question 40

Asbestos-related diseases include: ?ca outside lung

Answer 40

* Localized fibrous plaques or, rarely, diffuse pleural fibrosis * Pleural effusions, recurrent * Parenchymal interstitial fibrosis (asbestosis) * Lung carcinoma * Mesothelioma * Laryngeal, ovarian, and perhaps other extrapulmonary neoplasms, including colon carcinoma * Increased risks for systemic autoimmune diseases and cardiovascular disease also have been proposed **increased incidence of asbestos-related cancers in family members of asbestos workers

Question 41

Asbestos occurs in two distinct geometric forms, x and x. The x form accounts for x% of the asbestos used in industry. x, even though less prevalent, are more pathogenic than x, particularly with respect to induction of mesothelioma, a malignant tumor derived from the lining cells of pleural surfaces

Answer 41

serpentine and amphibole. The serpentine chrysotile form accounts for 90% of the asbestos used in industry. Amphiboles, even though less prevalent, are more pathogenic than chrysotiles, particularly with respect to induction of mesothelioma, a malignant tumor derived from the lining cells of pleural surfaces

Question 42

One study of asbestos workers found a x increase of lung carcinoma with asbestos exposure alone, while asbestos exposure and smoking together led to a x fold increase in the risk.

Answer 42

One study of asbestos workers found a fivefold increase of lung carcinoma with asbestos exposure alone, while asbestos exposure and smoking together led to a 55-fold increase in the risk.

Question 43

Asbestosis is marked by x, which is distinguished from diffuse interstitial fibrosis resulting from other causes only by the presence of x.

Answer 43

Asbestosis is marked by diffuse pulmonary interstitial fibrosis, which is distinguished from diffuse interstitial fibrosis resulting from other causes only by the presence of asbestos bodies. Asbestos bodies are golden brown, fusiform or beaded rods with a translucent center that consist of asbestos fibers coated with an iron-containing proteinaceous material (Fig. 15.20). They arise when macrophages phagocytose asbestos fibers; the iron is presumably derived from phagocyte ferritin. Other inorganic particulates may become coated with similar iron-protein complexes and are called ferruginous bodies.

Question 44

In contrast to coal workers’ pneumoconiosis and silicosis, asbestosis begins in the x lobes and x, with the x and x lobes becoming affected as fibrosis progresses.

Answer 44

In contrast to coal workers’ pneumoconiosis and silicosis, asbestosis begins in the lower lobes and subpleurally, with the middle and upper lobes becoming affected as fibrosis progresses. They rarely appear fewer than 10 years after first exposure and are more common after 20 to 30 years

Question 45

Acute radiation pneumonitis (lymphocytic alveolitis or hypersensitivity pneumonitis) x months after irradiation in x% of patients, depending on dose and age.

Answer 45

1 to 6 months after irradiation in 3% to 44% of patients, depending on dose and age.

Question 46

Drug-Induced Lung Diseases.

Answer 46

cytotoxic drugs used in cancer therapy (e.g., bleomycin) cause pulmonary damage and fibrosis as a result of direct toxicity and by stimulating the influx of inflammatory cells into the alveoli. Amiodarone, a drug used to treat cardiac arrhythmias, is preferentially concentrated in the lung and causes significant pneumonitis in 5% to 15% of patients receiving it. Cough induced by angiotensin-converting enzyme inhibitors is very common. Illicit intravenous drug abuse most often causes lung infections. In addition, particulate matter used to cut drugs may lodge in the lung microvasculature, producing granulomatous inflammation and fibrosis.

Question 47

Sarcoidosis is a ... Common clinical features ... Demographics ...

Answer 47

Sarcoidosis is a systemic granulomatous disease of unknown cause that may involve many tissues and organs. The most common are bilateral hilar lymphadenopathy or parenchymal lung involvement, occurring in 90% of cases. Eye and skin lesions are next in frequency. Since other diseases, including mycobacterial and fungal infections and berylliosis, can also produce noncaseating granulomas, the diagnosis is one of exclusion. Sarcoidosis usually occurs in adults younger than 40 years of age but can affect any age group. The prevalence is higher in women. Uncommon in asians.

Question 48

Non necrotising granulomas are found in sarcoidosis. Laminated concretions composed of calcium and proteins known as x bodies and stellate inclusions known as x are found within giant cells in approximately x% of the granulomas. Organs affected ...

Answer 48

Laminated concretions composed of calcium and proteins known as Schaumann bodies and stellate inclusions known as asteroid bodies are found within giant cells in approximately 60% of the granulomas. Though characteristic, these microscopic features are not pathognomonic of sarcoidosis because asteroid and Schaumann bodies may be encountered in other granulomatous diseases (e.g., tuberculosis). The spleen is involved in about 75% of cases, but overt splenomegaly is seen in only 20% of cases. Skin 25% - erythema nodosum Ocular involvement, seen in 25% of cases, takes the form of iritis or iridocyclitis and may be bilateral or unilateral. The liver is affected slightly less often than the spleen. It may be moderately enlarged and typically contains scattered granulomas, more in portal triads than in the lobular parenchyma. The bone marrow is involved in about 20% of cases.

Question 49

The term hypersensitivity pneumonitis describes a x

Answer 49

The term hypersensitivity pneumonitis describes a spectrum of immunologically mediated, predominantly interstitial lung disorders caused by intense, often prolonged exposure to inhaled organic antigens. The presence of non-necrotizing granulomas in two-thirds of the patients suggests that T cell–mediated (type IV) hypersensitivity reactions against the implicated antigens have a pathogenic role.

Question 50

Most commonly, hypersensitivity pneumonitis results from the inhalation of organic dust containing antigens made up of the spores of x x, x, x x, or x x.

Answer 50

inhalation of organic dust containing antigens made up of the spores of thermophilic bacteria, fungi, animal proteins, or bacterial products. Numerous syndromes are described, depending on the occupation or exposure of the individual. Farmer’s lung results from exposure to dusts generated from humid, warm, newly harvested hay that permits the rapid proliferation of the spores of thermophilic actinomycetes. Pigeon breeder’s lung (bird fancier’s disease) is provoked by proteins from serum, excreta, or feathers of birds. Humidifier or air-conditioner lung is caused by thermophilic bacteria in heated water reservoirs. Pet birds and moldy basements are easily missed unless asked about specifically.

Question 51

Desquamative interstitial pneumonia is characterized by large collections of x in the airspaces of a current or former smoker.

Answer 51

macrophages

Question 52

Respiratory bronchiolitis–associated interstitial lung disease is marked by chronic inflammation and peribronchiolar fibrosis. It is a common histologic lesion in cigarette smokers. It is characterized by the presence of pigmented intraluminal x within first- and second-order respiratory bronchioles.

Answer 52

macrophages

Question 53

Pulmonary alveolar proteinosis (PAP) is a rare disease caused by defects in pulmonary macrophage function due to ... Classes of PAP ...

Answer 53

deficient granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling, which results in the accumulation of surfactant in the intra-alveolar and bronchiolar spaces. * Autoimmune PAP is caused by autoantibodies that bind and neutralize the function of GM-CSF. It occurs primarily in adults, represents 90% of all cases of PAP, and lacks any familial predisposition. * Secondary PAP is uncommon and is associated with diverse diseases, including hematopoietic disorders, malignancies, immunodeficiency disorders, lysinuric protein intolerance (an inborn error of amino acid metabolism), and acute silicosis and other inhalational syndromes. It is speculated that these diseases somehow impair GM-CSF–dependent signaling or downstream events involved in macrophage maturation or function, again leading to inadequate clearance of surfactant from alveolar spaces. * Hereditary PAP is extremely rare, occurs in neonates, and is caused by loss-of-function mutations in the genes that encode GM-CSF or the GM-CSF receptor.

Question 54

Pulmonary eosinophilia is divided into the following categories:

Answer 54

Acute eosinophilic pneumonia with respiratory failure. This is an acute illness of unknown cause. It has a rapid onset with fever, dyspnea, and hypoxemic respiratory failure. Secondary eosinophilia, which occurs in a number of parasitic, fungal, and bacterial infections; in hypersensitivity pneumonitis; in drug allergies; and in association with asthma, allergic bronchopulmonary aspergillosis, or Churg-Strauss syndrome, a form of vasculitis. Idiopathic chronic eosinophilic pneumonia, characterized by focal areas of cellular consolidation of the lung substance distributed chiefly in the periphery of the lung fields.

Question 55

Risk factors for pulmonary emboli

Answer 55

prolonged bed rest, leg surgery, severe trauma, congestive heart failure, use of oral contraceptives (especially those with high estrogen content), disseminated cancer, and inherited forms of hypercoagulability.

Question 56

Pulmonary hypertension is defined as a mean pulmonary artery pressure greater than or equal to x mm Hg at rest

Answer 56

25

Question 57

Pulmonary hypertension - five groups:

Answer 57

(1) pulmonary arterial hypertension, a diverse collection of disorders that all primarily impact small pulmonary muscular arteries (2) pulmonary hypertension due to left heart failure (3) pulmonary hypertension due to lung diseases and/or hypoxia (4) chronic thromboembolic pulmonary hypertension and other obstructions (5) pulmonary hypertension with unclear and/or multifactorial mechanisms.

Question 58

Pulmonary hypertension Up to x% of “idiopathic” cases (sometimes referred to as primary pulmonary hypertension) have a genetic basis, sometimes being inherited in families as an x trait. All forms of pulmonary hypertension are associated with x of the pulmonary muscular and elastic arteries and x hypertrophy.

Answer 58

80% AD Within these families, there is incomplete penetrance, and only 10% to 20% of the family members actually develop overt disease. All forms of pulmonary hypertension are associated with medial hypertrophy of the pulmonary muscular and elastic arteries and right ventricular hypertrophy.

Question 59

Diffuse Pulmonary Hemorrhage Syndromes. Name some...

Answer 59

Idiopathic pulmonary hemosiderosis is a rare disorder characterized by intermittent, diffuse alveolar hemorrhage. Most cases occur in young children Goodpasture Syndrome (Anti–Glomerular Basement Membrane Antibody Disease With Pulmonary Involvement). Goodpasture syndrome is an uncommon autoimmune disease in which kidney and lung injury are caused by circulating autoantibodies against the noncollagenous domain of the α3 chain of collagen IV. When only renal disease is caused by this antibody, it is called anti–glomerular basement membrane disease. The term Goodpasture syndrome applies to the 40% to 60% of patients who develop pulmonary hemorrhage in addition to renal disease. Although any age can be affected, most cases occur in the teens or 20s, and in contrast to many other autoimmune diseases, there is a male preponderance. The majority of patients are active smokers. Polyangiitis With Granulomatosis. Previously called Wegener granulomatosis, this autoimmune disease most often involves the upper respiratory tract and/ or the lungs, with hemoptysis being the common presenting symptom.

Question 60

Pneumonia Factors that impair resistance include x Local pulmonary defense mechanisms may also be compromised by many factors, including:

Answer 60

Factors that impair resistance include chronic diseases, immunologic deficiencies, treatment with immunosuppressive agents, and leukopenia. Local pulmonary defense mechanisms may also be compromised by many factors, including: * Loss or suppression of the cough reflex, as a result of altered sensorium (e.g., coma), anesthesia, neuromuscular disorders, drugs, or chest pain, any of which may lead to aspiration of gastric contents. * Dysfunction of the mucociliary apparatus, which can be caused by cigarette smoke, inhalation of hot or corrosive gases, viral diseases, or genetic defects of ciliary function (e.g., immotile cilia syndrome). * Accumulation of secretions in conditions such as cystic fibrosis and bronchial obstruction. * Interference with the phagocytic and bactericidal activities of alveolar macrophages by alcohol, tobacco smoke, anoxia, or oxygen intoxication. * Pulmonary congestion and edema.

Question 61

Pneumonia Syndromes

Answer 61

Question 62

x is the most common bacterial cause of acute exacerbations of COPD.

Answer 62

H. influenzae

Question 63

x most commonly causes hospital-acquired infections, it is mentioned here because of its occurrence in cystic fibrosis and immunocompromised patients.

Answer 63

Pseudomonas aeruginosa

Question 64

Pontiac fever

Answer 64

Legionella pneumophila Organ transplant recipients are particularly susceptible.

Question 65

In lobar pneumonia, four stages of the inflammatory response have classically been described:

Answer 65

congestion, red hepatization, gray hepatization, and resolution. In the first stage of congestion, the lung is heavy, boggy, and red. It is characterized by vascular engorgement, intra-alveolar edema fluid containing a few neutrophils, and the presence of bacteria, which may be numerous. In the next stage of red hepatization, there is massive confluent exudation, as neutrophils, red cells, and fibrin fill the alveolar spaces. On gross examination, the lobe is red, firm, and airless, with a liver-like consistency, hence the name hepatization. The third stage of gray hepatization is marked by progressive disintegration of red cells and the persistence of a fibrinosuppurative exudate, resulting in a color change to grayish-brown. In the final stage of resolution, the exudate within the alveolar spaces is broken down by enzymatic digestion to produce granular, semifluid debris that is resorbed, ingested by macrophages, expectorated, or organized by fibroblasts growing into it

Question 66

Complications of pneumonia include (1) tissue destruction and necrosis, causing abscess formation (2) (3)

Answer 66

(1) tissue destruction and necrosis, causing abscess formation. pneumococcal or Klebsiella infections (2) spread of infection to the pleural cavity, causing an intrapleural fibrinosuppurative reaction known as empyema (3) bacteremic dissemination to the heart valves, pericardium, brain, kidneys, spleen, or joints, causing abscesses, endocarditis, meningitis, or suppurative arthritis. abscess: aerobic and anaerobic streptococci, S. aureus, and a host of gram-negative organisms. Mixed infections often occur because of the important causal role played by inhalation of foreign material. Anaerobic organisms normally found in the oral cavity, including members of the Bacteroides, Fusobacterium, and Peptococcus genera, are the exclusive isolates in about 60% of cases. The causative organisms are introduced by the following mechanisms: • Aspiration of infective material (the most frequent cause). Risk factors include suppressed cough reflexes (e.g., acute alcohol intoxication, opioid abuse, coma, anesthesia, seizure disorders), severe dysphagia (e.g., neurologic deficits, esophageal disease), protracted vomiting, and poor dental hygiene. Aspiration first causes pneumonia, which progresses to tissue necrosis and formation of lung abscess. • Antecedent primary lung infection. Postpneumonic abscess formations are usually associated with S. aureus, K. pneumoniae, and pneumococcus. Posttransplant or otherwise immunosuppressed individuals are at special risk. • Septic embolism. Infected emboli may arise from thrombophlebitis in any portion of the systemic venous circulation or from the vegetations of infective bacterial endocarditis on the right side of the heart and lodge in the lung. • Neoplasia. Secondary infection is particularly common in bronchopulmonary segments obstructed by a primary or secondary malignancy (postobstructive pneumonia). • Miscellaneous. Traumatic penetrations of the lungs; direct extension of suppurative infections from the esophagus, spine, subphrenic space, or pleural cavity; and hematogenous seeding of the lung by pyogenic organisms all may lead to lung abscess formation.

Question 67

Hospital-acquired infections are serious and often life-threatening. x and x are the most common isolates.

Answer 67

Gram-positive cocci (mainly S. aureus) and gram-negative rods (Enterobacteriaceae and Pseudomonas species) are the most common isolates. H. influenzae and M. catarrhalis (both a ated with acute exacerbations of COPD K. pneumoniae (observed in patients who are chronic alcoholics)

Question 68

Pneumonia x are particularly common among children and young adults. They occur sporadically or as local epidemics in closed communities (schools, military camps, and prisons

Answer 68

Mycoplasma infections

Question 69

x infection is acquired by inhalation of dust particles from soil contaminated with bird or bat droppings that contain small spores (microconidia), the infectious form of the fungus.

Answer 69

Histoplasmosis capsulatum In the lungs of otherwise healthy adults, Histoplasma infections produce granulomas,

Question 70

Almost everyone who inhales the spores of x becomes infected and develops a delayed-type hypersensitivity reaction to the fungus, but most remain asymptomatic.

Answer 70

Coccidioidomycosis - Coccidioides immitis

Question 71

Causes of Pulmonary Infiltrates in Immunocompromised Hosts

Answer 71

Question 72

Pulmonary Disease in Human Immunodeficiency Virus Infection list pathogens Pulmonary disease accounts for 30% to 40% of hospitalizations in HIV-infected individuals. he CD4+ T-cell count determines the risk of infection with specific organisms. As a rule of thumb, bacterial and tubercular infections are more likely at higher CD4+ counts (>200 cells/mm3 ). x usually strikes at CD4+ counts less than 200 cells/mm3 , while x, x, and x infections are uncommon until the disease is very advanced (CD4+ counts less than 50 cells/mm3 ).

Answer 72

Despite the emphasis on opportunistic infections, it must be remembered that bacterial lower respiratory tract infections caused by the “usual” pathogens are among the most serious pulmonary disorders in HIV infection. The implicated organisms include S. pneumoniae, S. aureus, H. influenzae, and gram-negative rods. Bacterial pneumonias in HIV-infected persons are more common, more severe, and more often associated with bacteremia than in those without HIV infection. * Not all pulmonary infiltrates in HIV-infected individuals are infectious in etiology. A host of noninfectious diseases, including Kaposi sarcoma (Chapters 6 and 11), nonHodgkin lymphoma (Chapter 13), and lung cancer, occur with increased frequency and must be excluded. * The CD4+ T-cell count determines the risk of infection with specific organisms. As a rule of thumb, bacterial and tubercular infections are more likely at higher CD4+ counts (>200 cells/mm3 ). Pneumocystis pneumonia usually strikes at CD4+ counts less than 200 cells/mm3 , while CMV, fungal, and Mycobacterium avium-intracellulare complex infections are uncommon until the disease is very advanced (CD4+ counts less than 50 cells/mm3 ).

Question 73

x% of lung cancer worldwide occurs in never-smokers. This percentage is probably closer to x% in Western countries.

Answer 73

25% 10-15% These cancers occur more commonly in women, and most are adenocarcinomas, often with targetable mutations/co-mutations. Cancers in nonsmokers are more likely to have EGFR mutations and almost never have KRAS mutations; TP53 mutations are not uncommon, but occur less frequently than in smoking-related cancers.

Question 74

Major categories of lung cancers and relative prevalence

Answer 74

The relative proportions of the major categories are: * Adenocarcinoma (50%) * Squamous cell carcinoma (20%) * Small cell carcinoma (15%) * Large cell carcinoma (2%) * Other (13%)

Question 75

Adenocarcinoma in situ (formerly called x) is a lesion that is less than x cm in size and is composed entirely of dysplastic cells growing along pre-existing alveolar septa. The cells have more dysplasia than atypical adenomatous hyperplasia and may or may not have intracellular mucin

Answer 75

bronchioloalveolar carcinoma 3cm

Question 76

Lung cancer Adenocarcinoma is an invasive malignant epithelial tumor with glandular differentiation or mucin production by the tumor cells. Adenocarcinomas grow in various patterns, including: Compared with squamous cell cancers, these lesions are usually more x located and tend to be x.

Answer 76

acinar, lepidic, papillary, micropapillary, and solid. peripherally, smaller

Question 77

Tumors (xcm) with a small invasive component (xmm) associated with scarring and a peripheral lepidic growth pattern are called microinvasive adenocarcinoma.

Answer 77

≤3 cm ≤5 mm

Question 78

Small cell carcinoma is a highly malignant tumor with a strong relationship to cigarette smoking; only about x% occurs in nonsmokers. Tumors may arise in (location).

Answer 78

1% occurs in nonsmokers. Tumors may arise in major bronchi or in the periphery of the lung. There is no known pre-invasive phase. They are the most aggressive of lung tumors, metastasizing widely and virtually always proving to be fatal.

Question 79

Small cell carcinoma is quite sensitive to x and x, and approximately 10% of patients with limited disease survive for 5 years and may be cured.

Answer 79

Small cell carcinoma is quite sensitive to radiation therapy and chemotherapy, and approximately 10% of patients with limited disease survive for 5 years and may be cured.

Question 80

Paraneoplastic Syndromes.

Answer 80

* Antidiuretic hormone (ADH), inducing hyponatremia due to inappropriate ADH secretion * Adrenocorticotropic hormone (ACTH), producing Cushing syndrome * Parathormone, parathyroid hormone-related peptide, prostaglandin E, and some cytokines, all implicated in the hypercalcemia often seen with lung cancer * Calcitonin, causing hypocalcemia * Gonadotropins, causing gynecomastia * Serotonin and bradykinin, associated with the carcinoid syndrome

Question 81

Any histologic type of tumor may occasionally produce any one of the hormones, but tumors that produce ACTH and ADH are predominantly x carcinomas, whereas those that produce hypercalcemia are mostly x carcinomas.

Answer 81

small cell squamous cell Other systemic manifestations of lung carcinoma include the Lambert-Eaton myasthenic syndrome , in which muscle weakness is caused by autoantibodies (possibly elicited by tumor ionic channels) directed to the neuronal calcium channel; peripheral neuropathy, usually purely sensory; dermatologic abnormalities, including acanthosis nigricans; hematologic abnormalities, such as leukemoid reactions; hypercoagulable states, such as Trousseau syndrome (deep vein thrombosis and thromboembolism); and finally, a peculiar abnormality of connective tissue called hypertrophic pulmonary osteoarthropathy, associated with clubbing of the fingers.

Question 82

Carcinoid tumors represent x% of all lung tumors. Most patients with these tumors are younger than x years of age, and the incidence is equal for both sexes. Approximately x% of patients are nonsmokers.

Answer 82

1-5% 60 20-40% Carcinoids may arise centrally or may be peripheral.

Question 83

carcinoid syndrome, characterized by Approximately, x% of bronchial carcinoids give rise to this syndrome.

Answer 83

intermittent attacks of diarrhea, flushing, and cyanosis 10%

Question 84

Lymphangioleiomyomatosis is a pulmonary disorder that primarily affects x (age group)

Answer 84

young women of childbearing age.

Question 85

Mediastinal Neoplasms and Other Masses

Answer 85

Question 86

Hydatid disease is caused by ingestion of eggs of x and formation of cysts in organs where the parasite larvae are deposited.

Answer 86

Echinococcus spp

Question 87

In pressure-overload hypertrophy (e.g., due to hypertension or aortic stenosis), new sarcomeres are predominantly assembled in x to the long axes of cells, expanding the cross-sectional area of myocytes in ventricles and causing a concentric increase in wall thickness.

Answer 87

parallel * In contrast, volume-overload hypertrophy (e.g., due to valvular regurgitation) is characterized by new sarcomeres being assembled in series within existing sarcomeres, leading primarily to ventricular dilation. As a result, in dilation due to volume overload, or dilation that accompanies failure of a previously pressure overloaded heart, the wall thickness may be increased, normal, or less than normal. Consequently, heart weight, rather than wall thickness, is the best measure of hypertrophy in dilated hearts.

Question 88

Left-sided heart failure is most often caused by the following:

Answer 88

* IHD * Hypertension * Aortic and mitral valvular diseases * Primary myocardial diseases

Question 89

Frequencies of Congenital Cardiac Malformations

Answer 89

Question 90

The most important causes of right-to-left shunts are

Answer 90

tetralogy of Fallot (TOF), transposition of the great arteries (TGA), persistent truncus arteriosus, tricuspid atresia, and total anomalous pulmonary venous connection.

Question 91

left-to-right shunts (x) increase pulmonary blood flow but are not initially associated with cyanosis

Answer 91

(e.g., ASD, VSD, and patent ductus arteriosus [PDA] Eventually, pulmonary vascular resistance approaches systemic levels, and the original left-to-right shunt becomes a right-to-left shunt that introduces poorly oxygenated blood into the systemic circulation (Eisenmenger syndrome).

Question 92

ASD/VSDs are usually asymptomatic until adulthood.

Answer 92

ASD Although VSDs are more common, most close spontaneously. Consequently, ASDs—which are less likely to close spontaneously—are the most common defects to be diagnosed in adults.

Question 93

The foramen ovale closes permanently in approximately 80% of people by x years of age.

Answer 93

2

Question 94

VSDs are classified according to their location and magnitude. About x% occur in the region of the membranous interventricular septum

Answer 94

90%

Question 95

x produces a characteristic, continuous, harsh “machinery-like” murmur.

Answer 95

PDA

Question 96

The four cardinal features of TOF are

Answer 96

(1) VSD, (2) obstruction of the right ventricular outflow tract (subpulmonic stenosis), (3) an aorta that overrides the VSD, and (4) right ventricular hypertrophy

Question 97

Evolution of Morphologic Changes in Myocardial Infarction

Answer 97

Question 98

Disorders Predisposing to Cor Pulmonale

Answer 98

Question 99

Etiology of Acquired Heart Valve Disease

Answer 99

Question 100

Rheumatic fever (RF) is x

Answer 100

Rheumatic fever (RF) is an acute, immunologically mediated, multisystem inflammatory disease classically occurring a few weeks after group A streptococcal pharyngitis; Acute rheumatic fever results from host immune responses to group A streptococcal antigens that cross-react with host proteins. Acute RF typically appears 10 days to 6 weeks after a group A streptococcal infection in about 3% of patients antibodies and CD4+ T cells directed against streptococcal M proteins can also in some cases recognize cardiac self antigens.

Question 101

During acute RF, focal inflammatory lesions are found in various tissues. Distinctive lesions in the heart—called x—are composed of foci of T lymphocytes, occasional plasma cells, and plump activated macrophages called cells. These macrophages have abundant cytoplasm and central roundto-ovoid nuclei (occasionally binucleate) in which the chromatin condenses into a central, slender, wavy ribbon (hence the designation “caterpillar cells”).

Answer 101

Aschoff bodies Anitschkow Overlying these necrotic foci and along the lines of closure are small (1 to 2 mm) vegetations, called verrucae. Thus, RHD is one of the forms of vegetative valve disease, each of which exhibit their own characteristic morphologic features (Fig. 12.23). Subendocardial lesions, perhaps exacerbated by regurgitant jets, can induce irregular thickenings called MacCallum plaques, usually in the left atrium. The cardinal anatomic changes of the mitral valve in chronic RHD are leaflet thickening, commissural fusion and shortening, and thickening and fusion of the tendinous cords

Question 102

Rheumatic fever is characterized by a constellation manifestations:

Answer 102

* Migratory polyarthritis of the large joints * Pancarditis (myocarditis, pericarditis, or endocarditis) * Subcutaneous nodules (typically on extensor surfaces of extremities) * Erythema marginatum, an irregular circinate skin rash * Sydenham chorea, a neurologic disorder with involuntary rapid movements

Question 103

Infective endocarditis is a

Answer 103

microbial infection of the heart valves or the mural endocardium that leads to the formation of vegetations composed of thrombotic debris and organisms, often associated with destruction of the underlying cardiac tissues.

Question 104

Noninfected (sterile) vegetations occur in nonbacterial thrombotic endocarditis (NBTE) and the endocarditis of x

Answer 104

systemic lupus erythematosus (SLE).

Question 105

Cardiomyopathies: Functional Patterns and Causes

Answer 105

Question 106

DCM is probably familial in up to x% of cases. Other causes?

Answer 106

50%. titin truncation mutations representing up to 20% of cases of DCM. DCM is characterized morphologically and functionally by progressive cardiac dilation and contractile (systolic) dysfunction, usually with concomitant hypertrophy. - Myocarditis - Alcohol and other toxins - Childbirth. Peripartum cardiomyopathy can occur late in pregnancy or up to 5 months postpartum - Iron overload in the heart can result from either h tary hemochromatosis or from multiple transfusions - Supraphysiologic stress can also result in DCM. This can happen with persistent tachycardia, hyperthyroidism, or even during development, as in the fetuses of insulin-dependent diabetic mothers - Takotsubo cardiomyopathy is an entity characterized by left ventricular contractile dysfunction after extreme psychological stress (

Question 107

Causes and consequences of dilated and hypertrophic cardiomyopathy. DCM vs hypertrophic CM inheritance, dysfunction

Answer 107

DCM results in systolic (contractile) dysfunction. HCM results in diastolic (relaxation) dysfunction.

Question 108

Pattern of transmission is x with variable penetrance. HCM is most commonly caused by mutations in any one of several genes that encode x proteins;

Answer 108

autosomal dominant sarcomeric

Question 109

The essential feature of HCM is x, usually without ventricular dilation

Answer 109

massive myocardial hypertrophy The classic pattern involves disproportionate thickening of the ventricular septum relative to the left ventricle free wall, termed asymmetric septal hypertrophy

Question 110

To be considered DCM, the heart should have no x

Answer 110

primary valvular alterations

Question 111

Hypertrophic cardiomyopathy (HCM) is a common (1 in x prevalence), clinically heterogeneous, genetic disorder characterized by myocardial hypertrophy, poorly compliant left ventricular myocardium leading to abnormal diastolic filling, and (in about one-third of cases) intermittent ventricular outflow obstruction.

Answer 111

500 The two most common diseases that must be distinguished clinically from HCM are deposition diseases (e.g., amyloidosis, Fabry disease) and hypertensive heart disease coupled with agerelated subaortic septal hypertrophy

Question 112

Restrictive cardiomyopathy is characterized by a primary decrease in ventricular compliance, resulting in impaired x

Answer 112

ventricular diastolic filling

Question 113

Restrictive cardiomyopathy can be x or associated with distinct disorders that affect the myocardium, principally x

Answer 113

idiopathic amyloidosis, sarcoidosis, radiation-induced fibrosis, metastatic tumors, or the accumulation of metabolites from inborn errors of metabolism.

Question 114

Major Causes of Myocarditis Nonviral agents are also important causes of infectious myocarditis, particularly the protozoan x, the agent of x disease

Answer 114

Trypanosoma cruzi, the agent of Chagas disease Cardiotoxic Drugs: many different conventional chemotherapeutic agents, as well as tyrosine kinase inhibitors. The anthracyclines doxorubicin and daunorubicin are the chemotherapeutic agents most often associated with toxic myocardial injury; Radiation

Question 115

Causes of Pericarditis

Answer 115

Serous pericarditis is characteristically produced by noninfectious inflammatory diseases, including rheumatic fever, SLE, and scleroderma, as well as tumors and uremia Fibrinous and serofibrinous pericarditis are the most frequent types of pericarditis Purulent or suppurative pericarditis reflects an active infection caused by microbial invasion of the pericardial space; this can occur through the following: * Direct extension from neighboring infections, such as an empyema of the pleural cavity, lobar pneumonia, mediastinal infections, or extension of a ring abscess through the myocardium or aortic root * Seeding from the blood * Lymphatic extension * Direct introduction during cardiotomy

Question 116

Primary cardiac tumors are uncommon; moreover, most are (fortunately) benign. The five most common tumors have no malignant potential and account for almost 90% of all primary heart tumors. In descending order of frequency (combined pediatric and adult populations), these are

Answer 116

myxomas, fibromas, lipomas, papillary fibroelastomas, and rhabdomyomas. About 90% of myxomas arise in the atria, with a left-to-right ratio of approximately 4:1. Myxomas range from small (<1 cm) to large (≥10 cm) and can be sessile or pedunculated lesions

Question 117

x are the most frequent primary tumor of the pediatric heart; they are commonly discovered in the first years of life during an evaluation for a valve or other flow obstruction. Causes/associations

Answer 117

Rhabdomyomas Approximately one-half of cardiac rhabdomyomas are due to sporadic mutations; the other 50% of cases are associated with tuberous sclerosis

Question 118

TB risk factors

Answer 118

disease of older adults, immigrants from high-burden countries, those living in crowded settings (prisons, homeless shelters, long-term care), and people with AIDS. Certain disease states also increase the risk: diabetes, Hodgkin lymphoma, chronic lung disease (particularly silicosis), chronic renal failure, malnutrition, alcoholism, and immunosuppression.

Question 119

Primary TB presentation: ... x (disease) is the greatest risk factor for progression to active disease

Answer 119

primary tuberculosis is asymptomatic, although it may cause fever and pleural effusion. Generally, the only evidence of infection, if any remains, is a tiny, fibrocalcific pulmonary nodule at the site of the infection. Viable organisms may remain dormant in such lesions for decades. If immune defenses are lowered, the infection may be reactivated, producing communicable and potentially life-threatening disease. AIDS is the greatest risk factor for progression to active disease, due to the loss of immunologic control of the organism

Question 120

Primary vs secondary TB

Answer 120

primary tuberculosis, which occurs with the first infection, and secondary tuberculosis, which occurs in an individual who has been previously infected by M. tuberculosis Primary tuberculosis is the form of disease that develops in a previously unexposed and therefore unsensitized person. Secondary tuberculosis is the pattern of disease that arises in a previously sensitized host. It may follow shortly after primary tuberculosis, but more commonly it appears months to years after the initial infection, usually when host resistance is weakened.

Question 121

Natural history of TB

Answer 121

Question 122

x is a leading cause of death in people with AIDS.

Answer 122

Tuberculosis is a leading cause of death in people with AIDS. All stages of HIV infection are associated with an increased risk of tuberculosis.

Question 123

TB This combination of parenchymal lung lesion and nodal involvement is referred to as the x

Answer 123

Ghon complex Sensitization develops, a 1- to 1.5-cm area of gray-white inflammation with consolidation emerges, known as the Ghon focus. In most cases, the center of this focus undergoes caseous necrosis

Question 124

Major Risk Factors for Atherosclerosis Nonmodifiable and modifiable

Answer 124

Question 125

Pathogenesis of Atherosclerosis

Answer 125

This model views atherosclerosis as a chronic inflammatory and healing response of the arterial wall to endothelial injury. Lesion progression occurs through interaction of modified lipoproteins, macrophages, and T lymphocytes with ECs and SMCs of the arterial wall * Endothelial injury and dysfunction, causing (among other things) increased vascular permeability, leukocyte adhesion, and thrombosis. Most important causes of endothelial dysfunction are hemodynamic disturbances, hypercholesterolemia, and inflammation. * Accumulation of lipoproteins (mainly LDL and its oxidized forms) in the vessel wall. * Monocyte adhesion to the endothelium, followed by migration into the intima and transformation into macrophages and foam cells. * Platelet adhesion. * Factor release from activated platelets, macrophages, and vascular wall cells, inducing SMC recruitment, either from the media or from circulating precursors. * SMC proliferation, ECM production, and recruitment of T cells. * Lipid accumulation both extracellularly and within cells (macrophages and SMCs). * Calcification of ECM and necrotic debris late in the pathogenesis.

Question 126

Fatty streaks.

Answer 126

Fatty streaks are composed primarily of lipid-filled foamy macrophages. Beginning as small flat yellow macules, these can eventually coalesce into elongated streaks 1 cm long or longer. The lesions are not particularly raised and do not cause any significant flow disturbance. Although fatty streaks can evolve into plaques, not all are destined to become advanced lesions. Aortas of infants can exhibit fatty streaks, and such lesions are present in virtually all adolescents, even those without known risk factors. That coronary fatty streaks begin to form in adolescence at the same anatomic sites that later tend to develop plaques suggests a temporal evolution of these lesions.

Question 127

The most extensively involved vessels in atherosclerosis are the:

Answer 127

lower abdominal aorta and iliac arteries, the coronary arteries, the popliteal arteries, the internal carotid arteries, and the vessels of the circle of Willis

Question 128

Atherosclerotic plaques have four principal components:

Answer 128

(1) cells including variable numbers of SMCs, macrophages, and T lymphocytes; (2) ECM including collagen, elastic fibers, and proteoglycans; (3) intracellular and extracellular lipids; and (4) calcifications in later stage plaques

Question 129

Atherosclerotic plaques are susceptible to clinically important pathologic changes. Consequences of Atherosclerotic Disease

Answer 129

* Rupture, ulceration, or erosion of the surface of atheromatous plaques exposes the blood stream to highly thrombogenic substances and leads to thrombosis, which can partially or completely occlude the vessel lumen. If the patient survives, the thrombus may organize and become incorporated into the growing plaque. * Hemorrhage into a plaque. Rupture of the overlying fibrous cap or of the thin-walled vessels in the areas of neovascularization can cause intraplaque hemorrhage; a contained hematoma may expand the plaque or induce plaque rupture. * Atheroembolism. Plaque rupture can discharge atherosclerotic debris into the blood stream, producing microemboli. * Aneurysm formation. Atherosclerosis-induced pressure or ischemic atrophy of the underlying media, with loss of elastic tissue, causes weakness and potential rupture. Myocardial infarction (heart attack), cerebral infarction (stroke), aortic aneurysms, and peripheral vascular disease (gangrene of the legs) are the major consequences of atherosclerosis.

Question 130

Thymic hypoplasia or aplasia is seen in x, which is marked by severe defects in cell-mediated immunity and variable abnormalities of parathyroid development and function.

Answer 130

DiGeorge syndrome DiGeorge syndrome is often associated with other developmental defects as part of the 22q11 deletion syndrome.