The Lung Flashcards
(440 cards)
1
Q
Mention 7 developmental defects of the lung.
A
- Agenesis or hypoplasia of both lungs, one lung, or single lobes.
- Tracheal and bronchial anomalies (atresia, stenosis, tracheoesophageal fistula)
- Vascular anomalies
- Congenital lobar overinflation (emphysema)
- Foregut cysts
- Congenital pulmonary airway malformation
- Pulmonary sequestrations
2
Q
What happens in pulmonary hypoplasia?
A
Defective development of both lungs (one may be more affected) resulting in decrease weight, volume and acini disproportional to the body weight and gestational age.
Variety of causes : e.g. Congenital diaphragmatic hernia - oligohydramnions.
3
Q
What happens in foregut cysts?
A
Abnormal detachment of primitive foregut. Most often located in the hilum or middle mediastinum.
They can be bronchogenic (most common), esophageal and enteric.
Surgery resection is curative.
4
Q
What happens in pulmonary sequestration?
A
Presence of discrete mass of lung tissue without normal connection to the airway system.
They can be extralobar or intralobar.
Blood supply arises from the aorta or its branches.
5
Q
What happens to neonatal atelectasis?
A
Incomplete expansion of the lungs or collapse of previously inflated lungs, producing areas of relatively airless pulmonary parenchyma.
6
Q
How is acquired atelectasis divided?
A
- Resorption (or obstruction) atelectasis
- Compression atelectasis
- Contraction atelectasis
7
Q
What happens in resorption atelectasis?
A
Complete obstruction of an airway, which in time leads to resorption of the oxygen trapped in the dependent alveoli.
The mediastinum shifts towards the atelectatic lung.
Caused mainly by mucus plugs, exudate within smaller bronchi.
8
Q
What happens in compression atelectasis?
A
The pleural cavity is partially or completely filled by fluid exudate, tumor, blood or air (pneumothorax).
The mediastinum shifts away from the affected lung.
9
Q
What happens in contraction atelectasis?
A
Local or generalized fibrotic changes in the lung or pleura prevent full expansion.
10
Q
Is atelectasis reversible?
A
Yes, except that caused by contraction.
11
Q
What are the two principal causes of pulmonary edema?
A
- From hemodynamic disturbances (hemodynamic/ cardiogenic edema).
- Direct increases in capillary permeability as a result of microvascular injury.
12
Q
What happens in hemodynamic pulmonary edema?
A
- Increased hemodynamic pressure (as in left-side congestive heart failure).
- Heavy, wet lungs.
- Initially, fluid accumulates in the lower lobes.
- Histologically : the alveolar capillaries are engorged - intra alveolar granular pink precipitate is seen.
- Presence of hemosiderin-laden macrophages.
13
Q
What happens in acute respiratory distress syndrome (ARDS)?
A
The integrity of microvascular endothelium and alveolar epithelium is compromised by injury of one or both (more common).
14
Q
What markers in the serum can be detected in ARDS that count for endothelial injury?
A
- Endothelin
2. vWF
15
Q
What shows epithelial injury in ARDS ?
A
- Swelling
- Vacuolization
- Bleb formation
- Frank necrosis
16
Q
What are the acute consequences of damage to the alveolar capillary membrane in ARDS ?
A
- Increased vascular permeability
- Alveolar flooding
- Loss of diffusion capacity
- Widespread surfactant abnormalities (damage of type II pneumocytes).
17
Q
How hyaline membranes are formed in the ARDS / ALI ?
A
Inspissation of protein rich edema fluid that entraps debris of dead alveolar epithelial cells.
18
Q
What is the principal cause of ARDS ?
A
An imbalance between pro-inflammatory and anti-inflammatory mediators.
19
Q
What mediator is thought to shift the balance towards inflammation in the ARDS ?
A
NF-kB
20
Q
How are neutrophils sequestered in the lung in ARDS ?
A
- Cytokines like IL-8 and TNF, that upregulate adhesion molecules.
- Activated neutrophils become stiff and less deformable and thus get trapped in the narrow capillary beds of the lung.
21
Q
What are the principal symptoms of ALI?
A
- Dyspnea and tachypnea
- Increasing cyanosis and hypoxemia
- Respiratory failure
- Diffuse bilateral infiltrates
22
Q
Are the functional abnormalities in ALI evenly distributed throughout the lungs?
A
No, there are areas that are infiltrated, consolidated, or collapsed and regions that have nearly normal levels of compliance and ventilation.
23
Q
What happens in acute interstitial pneumonia?
A
- Widespread ALI with a rapidly progressive clinical course of unknown etiology.
- Uncommon disease
- Mean age 50 with no sex predilection
- Mortality : 33-74% within 1-2 months.
24
Q
What is the classification of chronic noninfectious diffuse pulmonary diseases?
A
- Obstructive (or airway) diseases : increase in resistance to airflow due to partial or complete obstruction.
- Restrictive diseases : reduced expansion of the lung parenchyma and decrease total lung capacity.
25
Under what conditions occur restrictive diseases?
1. Chest wall disorders (neuromuscular diseases such as poliomyelitis, severe obesity, kyphoscoliosis)
2. Chronic interstitial and infiltrative diseases (pneumoconioses, interstitial fibrosis of unknown etiology)
26
What are the 4 major obstructive pulmonary diseases?
1. Emphysema
2. Chronic bronchitis
3. Asthma
4. Bronchiectasis
27
To what diseases is COPD refer to?
1. Emphysema
| 2. Chronic bronchitis
28
What is the main cause of COPD ?
Long term heavy cigarette smoking - 10% are nonsmokers.
29
What happens in emphysema?
Irreversible enlargement of the air spaces distal to the terminal bronchiole, accompanied by destruction of the walls without obvious fibrosis.
30
What is the incidence of emphysema?
4th leading cause of morbidity and mortality in the USA.
| Women and African Americans are more susceptible than other groups.
31
What are the types of emphysema?
1. Centriacinar (95% of cases)
2. Panacinar (almost the rest of cases)
3. Paraseptal
4. Irregular
32
What happens in centriacinar (centrilobular) emphysema?
The central or proximal parts of the acini, formed by respiratory bronchioles, are affected, whereas distal alveoli are spared.
33
Where is centriacinar emphysema most commonly found?
In the upper lobes, particularly in the apical segments.
34
What happens in panacinar emphysema?
The acini are uniformly enlarged from the level of the respiratory bronchiole to the terminal blind alveoli.
35
Where panacinar emphysema occur more commonly?
In the lower zones and in the anterior margins of the lung, and it is usually most severe at the bases.
36
What type of emphysema is associated with α1-anti trypsin?
Panacinar emphysema
37
What happens in distal acinar (paraseptal) emphysema?
The proximal portion of the acinus is normal, and the distal part is predominantly involved.
38
What happens in irregular emphysema (airspace enlargement with fibrosis)?
The acinus is irregularly involved, is almost invariably associated with scarring.
39
What is the pathogenesis of emphysema ?
The most plausible hypothesis to account for the destruction of alveolar walls is the protease-antiprotease mechanism, aided and abetted by imbalance of oxidants and anti oxidants.
40
Describe briefly the "picture" of emphysema.
1. Mild chronic inflammation throughout the airways, parenchyma and pulmonary vasculature.
2. Macrophages, CD8/4+ T lymphocytes and neutrophils in various parts of the lung.
3. LTB4, IL-8 , TNF and other mediators.
41
In what evidence is the protease-antiprotease imbalance hypothesis based on?
The observation that patients with α1-AT deficiency have a markedly enhanced tendency to develop pulmonary emphysema (which is compounded by smoking).
42
What is the role of the α1-AT and where is its gene mapped?
Inhibitor of proteases, especially elastase which is secreted by neutrophils.
In the Pi locus (proteinase inhibitor locus) on chromosome 14.
43
What is the incidence of α1-ΑΤ deficiency (homozygous for the Z allele)?
0.012% (USA)
44
Describe briefly the sequence of events in a patient with α1-ΑΤ deficiency, that lead to emphysema.
1. Neutrophils (principal source of cellular proteases) are normally sequestered in the peripheral capillaries and a few gain access to the alveolar spaces.
2. Any stimulus that increases the number of leukocytes in the lung or the release of their protease-containing granules increases proteolytic activity.
3. With low levels of α-ΑΤ, elastic tissue destruction is unchecked and emphysema results.
45
How the protease-antiprotease imbalance hypothesis explain the effect of smoking in the development of emphysema?
1. In smokers, neutrophils and macrophages accumulate in alveoli.
2. Accumulated neutrophils are activated and release their granules, rich in a variety of cellular proteases (elastase, proteinase 3 and cathepsin G) resulting in tissue damage.
3. Smoking also enhances elastase activity in macrophages (which is not inhibited by α1-ΑΤ).
46
Besides loss of elastic recoil, what other mechanisms are responsible for the obstruction of airflow in emphysema?
1. Goblet cell metaplasia with mucus plugging of the lumen.
2. Inflammatory infiltration of the walls with neutrophils, macrophages, B cells , CD4/8 + T cells.
3. Smooth muscle hypertrophy and peribronchial fibrosis.
47
What are the morphological changes of advanced emphysema?
1. Voluminous lungs, often overlapping the heart.
2. The upper 2/3 of the lungs are more severely affected.
3. Microscopically, there are abnormally large alveoli separated by thin septa with only focal centriacinar fibrosis.
4. Loss of attachment of the alveoli to the outer wall of small airways.
5. Enlargement of the pores of Kohn.
6. As alveolar walls are destroyed, there is a decrease in the capillary bed.
48
When do the clinical manifestations of emphysema firstly appear?
Until at least one third of the functioning pulmonary parenchyma is damaged.
49
What are the major symptoms of emphysema?
1. Dyspnea
2. Cough or wheezing
3. Weight loss (severe)
4. Barrel-chested patient + Prolonged expiration, in a hunched over position p, breathing through pursed lips.
50
What are the main causes of death in patients with emphysema?
1. Respiratory acidosis and coma
2. Right-sided heart failure
3. Massive collapse of the lungs secondary to pneumothorax.
51
Mention 4 other types of emphysema.
1. Compensatory hyperinflation (emphysema)
2. Obstructive overinflation
3. Bullous emphysema
4. Interstitial emphysema
52
What is the clinical definition of chronic bronchitis?
Persistent cough with sputum production for at least 3 months and in at least 2 consecutive yeas, in the absence of any other identifiable cause.
53
When persistent from years, how can chronic bronchitis progress?
1. To COPD
2. To cor pulmonale and heart failure
3. Atypical metaplasia and dysplasia of the respiratory epithelium, providing a rich soil for cancerous malformation.
54
What is the primary factor in the genesis of chronic bronchitis?
Inhaled substances such as tobacco smoke (90% of patients are smokers), dust from grain, cotton and silica.
55
What is the earliest feature of chronic bronchitis?
Hypersecretion of mucus in the large airways, associated with hypertrophy of the submucosal glands.
56
What happens as chronic bronchitis persist?
A marked increase in goblet cells of small airways - small bronchi and bronchioles - leading to excessive mucus production that contributes to airway obstruction.
57
What is the role of infection in chronic bronchitis?
Secondary. Not responsible for the initiation of chronic bronchitis, but significant in maintaining it.
58
What are the morphological features of chronic bronchitis?
1. Hyperemia, swelling and edema of the mucous membranes, accompanied by excessive mucous secretions.
2. Chronic inflammation of the airways.
3. Enlargement of the submucosal glands.
4. Increased Reid index.
5. Metaplasia of bronchial epithelium - squamous + dysplasia
59
What happens principally in asthma?
Chronic inflammatory disorder of the airways that causes recurrent episodes of wheezing, breathlessness, chest-tightness, and cough, particularly at night and/or in the early morning.
60
What are the hallmarks of asthma?
1. Increased airway responsiveness to a variety of stimuli - resulting in episodic bronchoconstriction.
2. Inflammation of the bronchial walls.
3. Increased mucus secretion.
61
What are the two major types of asthma?
1. Atopic
| 2. Non-atopic
62
What happens in atopic asthma?
1. Most common type of asthma.
2. IgE-mediated hypersensitivity type I reaction.
3. Begins in childhood by environmental factors.
4. Common positive family history of asthma.
63
What happens in non atopic asthma?
1. No evidence of allergen sensitization.
2. Skin test results are negative.
3. Less common positive family history.
4. Common triggers are respiratory infections due to viruses.
5. Virus-induced inflammation of the respiratory mucosa lowers the threshold of the subepithelial vagal receptors to irritants.
64
What happens in drug-induced asthma?
1. Small doses of aspirin can trigger asthmatic attacks.
2. Also urticaria.
3. Aspirin inhibits the COX pathway, but does not affect the Lipoxygenase route - LTs are bronchoconstrictors.
65
How is occupational asthma stimulated?
1. Fumes (epoxy resins, plastics).
2. Organic and chemical dusts (wood, cotton, platinum).
3. Gases (toluene).
4. Other chemicals (formaldehyde, penicillin products).
66
What are the major etiologic factors in atopic asthma?
1. Genetic predisposition to type I hypersensitivity ("atopy").
2. Exposure to environmental triggers (poorly defined).
67
What cytokines are secreted by T2H cells and what is their roles?
1. IL-4 : production of IgE.
2. IL-5 : activation of locally recruited eosinophils.
3. IL-13 : Mucus secretion + IgE production from B cells.
68
What happens in the early phase reactions (immediate hypersensitivity)?
1. Bronchoconstriction
2. Increased mucus production
3. Variable degrees of vasodilation - IVP.
69
What happens in the late phase reaction?
1. Inflammation - eosinophils, neutrophils and more T cells.
| 2. Many mediators - e.g. Eotaxin.
70
What are the "suspects" in acute asthma?
1. LTC4, D4, E4
2. Ach
3. Histamine
4. PGD2
5. PAF
6. IL-1, TNF, IL-6, Eotaxin
7. Neuropeptides
8. NO, Bradykinin and endothelins
71
What happens in airway remodeling?
1. Hypertrophy and hyperplasia of bronchial smooth muscle.
2. Epithelial injury.
3. Increased airway vascularity.
4. Increased subepithelial mucus gland hypertrophy/hyperplasia.
5. Deposition of subepithelial collagen.
72
How many genes have been reported to associate with asthma?
More than 100
73
Mention briefly the genetic components of asthma.
1. Chromosome 5q, near the gene encoding IL-3-4-5-9-13 and the IL-4 receptor + CD14 receptor.
2. Class II HLA alleles.
3. ADAM-33
4. β2-adrenergic receptor gene.
5. Mammalian chitinase family : YKL-40
74
What are the morphological features of asthma?
1. Macroscopically : occlusion of the bronchi and bronchioles by thick, tenacious, mucus plugs.
2. Histologically : the plugs contain Curschmann spirals.
3. Charcot-Leyden crystals : crystalloid made up from eosinophil lysophospholipase binding protein called galectin-10.
4. Airway remodeling.
75
What happens in bronciectasis?
Permanent dilation of the bronchi and bronchioles caused by destruction of the muscle and elastic tissue, resulting from or associated with chronic necrotizing infections.
76
Bronchiectasis develops in association with a variety of conditions. Mention some of them.
1. Congenital or hereditary conditions : cystic fibrosis, intralobar sequestration of the lung, immunodeficiency states, primary ciliary dyskinesia and Kartagener syndromes.
2. Post infectious conditions.
3. Bronchial obstruction
4. Other conditions (SLE, rheumatoid arthritis, inflammatory bowel disease).
77
What are the two major conditions associated with bronchiectasis?
Obstruction and Infection
78
What are the morphological features of bronchiectasis?
1. Affects the lower lobes, bilaterally, vertical air passages.
2. The airways are dilated up to 4 times normal.
3. In full blown active case : intense acute and chronic inflammatory exudation + desquamation of the epithelium + areas of necrotizing ulceration.
4. Fibrosis in chronic conditions.
79
What are the major symptoms of bronchiectasis?
1. Severe, persistent cough.
2. Expectoration of foul-smelling
3. Sometimes bloody sputum
4. In severe cases, dyspnea and orthopnea
5. Occasionally, life-threatening hemoptysis
80
What happens in chronic interstitial diseases?
Heterogenous group of disorders.
Inflammation and fibrosis of the pulmonary connective tissue, principally in the most peripheral and delicate intestitium in the alveolar wall.
81
What is the current concept for the pathogenesis of idiopathic pulmonary fibrosis (IPF)?
1. Repeated cycles of epithelial injury/activation by some unidentified agent.
2. Abnormal epithelial repair gives rise to exuberant fibroblastic/myofibroblastic proliferation.
82
Who is the driver of the process in IPF?
TGF-β1 - released from injured type I alveolar epithelial cells.
83
What are the morphological features of IPF?
1. Fibrosis of the lung parenchyma - lower lobe predominance - distinctive distribution in the subpleural regions and along the interlobular septa.
2. Patchy interstitial fibrosis
3. Fibroblastic foci
4. Honeycomb fibrosis - destruction of alveolar architecture and formation of cystic spaces lined by hyperplastic type II pneumocytes or bronchiolar epithelium.
5. Mild to moderate inflammation within the fibrotic areas.
6. Foci of squamous metaplasia and smooth muscle hyperplasia may be present.
84
What is the clinical course of IPF?
1. Begins insidiously with gradually increasing dyspnea on exertion.
2. Dry cough
3. 40-70 age of presentation
4. Hypoxemia - cyanosis
5. Unpredictable progress
6. Mean survival 3 years or less
7. Lung transplantation the only current solution
85
Where is a better prognosis? In patients with IPF or in patients with Non specific interstitial pneumonia (NSIP)?
NSIP
86
What are the morphological features of NSIP?
1. Cellular patterns : mild/moderate chronic inflammation
2. Fibrosing patterns : diffuse or patchy interstitial fibrosis without the temporal heterogeneity of UIP.
3. Fibroblastic foci and honeycombing are absent.
87
What is the clinical course of NSIP?
1. Patients present with dyspnea and cough - several months.
2. Typically between age 46-55.
3. Patients with cellular pattern (younger) have a better outcome than those with fibrosing pattern.
88
What are the symptoms and signs of cryptogenic organizing pneumonia?
1. Dyspnea and cough
2. Subpleural/peribronchial patchy areas of airspace consolidation.
3. Masson bodies : loose organizing connective tissue polypoid plugs.
4. No interstitial fibrosis + No honeycomb lung.
89
What is the progress of cryptogenic organizing pneumonia?
1. Some recover spontaneously.
| 2. Most need steroids for 6 months or longer for complete recovery.
90
Mention 3 diseases that usually have pulmonary involvement.
1. Rheumatoid arthritis
2. Systemic sclerosis (scleroderma)
3. SLE
91
What happens in Pneumoconioses?
Non-neoplastic lung reaction to inhalation of mineral dusts encountered in the workplace + organic - inorganic particulates + chemical fumes and vapors.
92
On what depends the pathogenesis of pneumoconioses?
1. The amount of dust retained in the lungs.
2. The size, the shape and therefore buoyancy of the particles.
3. Particle solubility and physiochemical reactivity.
4. The possible additional effects of other irritants (e.g. Concommitant tobacco smoking).
93
What is the size of the most dangerous particles that can accumulate in the lungs?
1-5μm because they may reach the terminal small airways and air sacs and settle in their linings.
94
What covers the spectrum of lung findings in coal workers?
1. Asymptomatic anthracosis
2. Simple CWP with little or no pulmonary dysfunction.
3. Complicated CWP, or progressive massive fibrosis.
95
What are the features of anthracosis?
1. Most innocuous pulmonary lesion in coal miners.
2. Inhaled carbon pigment is engulfed by alveolar/interstitial macrophages which then accumulate in the connective tissue along the lymphatics or in organized lymphoid tissue along the bronchi - lung hilus.
96
What are the characteristics of simple CWP?
1. Coal macules (1-2mm) + coal nodules (larger).
2. Coal macules : carbon-laden macrophages.
3. Coal nodules : also contain collagen fibers.
4. Upper lobes and upper zones of lower lobes more heavily involved.
5. Centrilobular emphysema occurs sometimes.
97
What are the features of complicated CWP?
1. Requires years to develop.
2. Intensely black scars 2-10cm.
3. Lesions consisting of dense collagen and pigment.
98
What is silicosis?
A lung disease caused by inhalation of crystalline silicon dioxide (silica).
99
What is currently the most prevalent chronic occupational disease in the world?
Silicosis
100
What are the pathogenetic features of silicosis?
1. Quartz is most commonly implicated in silicosis.
2. After inhalation the particles interact with epithelial cells + macrophages.
3. Silica causes activation + release of mediators by the macrophages.
101
What are the morphological features of silicosis?
1. Tiny, barely palpable, discrete pale to blackened nodules in the upper zones of the lung.
2. Nodules may coalesce into hard, collagenous scars.
3. Fibrotic lesions in the hilar lymph nodes and pleura.
4. Eggshell calcification in the lymph nodes.
5. May produce progressive massive fibrosis (PMF).
6. Nodular lesions : concentric layers of hyalinized collagen surrounded by a dense capsule of more condensed collagen.
102
What is the clinical course of silicosis?
1. No shortness of breath until late in course.
2. Impaired pulmonary function, but slow to kill.
3. Increased susceptibility for tuberculosis.
4. Relationship with lung cancer is controversial.
103
What are the disorders that occupational exposure to asbestos is linked to?
1. Localized fibrous plaques - rarely diffuse pleural fibrosis.
2. Pleural effusions
3. Parenchymal interstitial fibrosis (asbestosis)
4. Lung carcinoma
5. Mesothelioma
6. Laryngeal + other extrapulmonary carcinomas (colon carcinoma)
104
What characteristics of asbestos dictate whether it causes disease?
1. Size
2. Shape
3. Solubility
4. Concentration
105
What are the two forms of asbestos?
Serpentine (widely used) and amphibole (more pathogenic, especially in mesotheliomas).
106
What are the oncogenic effects of asbestos?
Asbestos can act as a tumor initiator and promoter.
107
What is asbestos' relationship with tobacco smoke?
There is synergy between tobacco smoke and development of lung carcinoma in asbestos workers (55-fold increased risk)!
108
Asbestosis is marked by diffuse pulmonary interstitial fibrosis, which is indistinguishable from diffuse interstitial fibrosis resulting from other causes. What can lead us to diagnose asbestosis?
The presence of asbestos bodies.
109
What are the asbestos bodies?
Golden brown, fusiform or beaded rods with a translucent center and consisting of asbestos fibers coated with an iron containing proteinaceous material.
110
How is asbestosis begins?
As fibrosis around respiratory bronchioles and alveolar ducts, extending to involve adjacent alveolar sacs and alveoli.
111
What part of the lung is firstly affected by asbestosis (in contrast to CWP and silicosis)?
The lower lobes and subpleurally.
112
What is the most common manifestation of asbestos?
Pleural plaques : well circumscribed plaques of dense collagen containing calcium.
Anterior and posterolateral aspects of the parietal pleura and over the domes of the diaphragm.
113
Is there a correlation between the size and the number of pleural plaques and the exposure to asbestos?
No, they do not correlate neither with the time of exposure nor with the level of exposure.
114
What is the relationship of asbestosis with lung cancer?
Both lung carcinomas and mesotheliomas (pleural and peritoneal) develop in workers exposed to asbestos.
115
What are the signs and symptoms of asbestosis?
1. Dyspnea
2. Cough with sputum
3. It takes at least 10-20 years for the manifestations to occur.
4. Honeycomb pattern develops.
5. May remain static or progress to respiratory failure, cor pulmonale, and death.
6. Pleural plaques are asymptomatic.
7. Complication with cancer offers a grim prognosis.
116
Mention 6 examples of drug induced pulmonary disease.
1. Bleomycin - pneumonitis and fibrosis
2. Methotrexate - hypersensitivity pneumonitis
3. Amiodarone - pneumonitis and fibrosis
4. Nitrofurantoin - hypersensitivity pneumonitis
5. Aspirin - bronchospasm
6. β-antagonists - bronchospasm
117
What is sarcoidosis?
A systemic disease of unknown cause characterized by noncaseating granulomas in many tissues and organs.
118
What are the most common clinical findings?
1. Bilateral hilar lymphadenopathy or lung involvement in 90% of cases.
2. Eye and skin lesions.
119
Although the etiology of sarcoidosis remains unknown, what the lines of evidence suggest?
A disease of disordered immune regulation in genetically predisposed individuals exposed to certain environmental agents.
120
What are the immunological abnormalities of sarcoid granulomas?
1. Intra-alveolar and interstitial accumulation of CD4+ T cells, resulting in CD4/CD8 T cell ratios ranging from 5:1 to 15:1.
2. Increased levels of IL-2 and IFN-γ (TH1 cytokines) resulting in T cell expansion and macrophage activation respectively.
3. Increased levels of IL-8, TNF, MIP-1α that favor recruitment of T cells and monocytes and contribute to the formation of granulomas.
121
What are the systemic immunological abnormalities in individuals with sarcoidosis?
1. Anergy to common skin test antigens.
| 2. Polyclonal hypergammaglobulinemia - another manifestation of helper T cell dysregulation.
122
What are the genetic factors for sarcoidosis?
1. Familial and racial clustering of cases.
| 2. The association with certain types of HLA genotypes.
123
What are the environmental factors for sarcoidosis?
1. The most tenuous of all associations in the pathogenesis of sarcoidosis.
2. Suspicion falls on putative microbes (e.g. rickettsia)
124
What are the general morphological features of sarcoidosis?
1. Classic non caseating granulomas.
2. Aggregation of epithelioid cells, often with Langhans or foreign body-type giant cells.
3. Central necrosis is unusual.
4. Hyaline fibrous scars (with chronicity)
5. Schaumann bodies (calcium and proteins)
6. Asteroid bodies (stellate inclusions enclosed within giant cells - 60% of cases)
125
Sarcoidosis is a systemic disease. Mention the principal organs that are affected.
1. Lungs (common site).
2. Lymph nodes (in almost all cases) - hilar and mediastinal but any other may be involved - enlarged, discrete and sometimes calcified.
3. Spleen (microscopically affected in 75% but enlargement occurs only in 20%).
4. Liver (slightly less often than the spleen).
5. Bone marrow (20%)
6. Skin lesions (33-50%)
7. The eye and associated glands + salivary glands (20-50%)
8. Muscle involvement (usually asymptomatic)
126
What is hypersensitivity pneumonia?
A spectrum of immunologically mediated, predominantly interstitial, lung disorders caused by intense, often prolonged exposure to inhaled organic antigens.
In contrast with asthma, involves primarily the alveoli.
127
How farmer's lung occur?
From exposure to dust generated by harvested, humid, warm hay - permits the rapid proliferation of the spores of thermophilic actinomycetes.
128
How is Pigeon breeder's lung occur?
Provoked by proteins of serum, excreta, or feathers of birds.
129
How is humidifier or air-conditioner lung occur?
Caused by thermophilic bacteria in heated water reservoirs.
130
What are the lines of evidence that suggest that hypersensitivity pneumonitis is an immunologically mediated disease?
1. Increased levels of MIP-1α and IL-8 in bronchoalveolar lavage specimens.
2. Also increased CD4/8 T cells.
3. Most patients have specific antibodies - suggestive of type III hypersensitivity.
4. Complement and immunoglobulins within the vessel walls- indicating type III hypersensitivity.
5. Presence of non caseating granulomas in 66% suggests T cell mediated (type IV) delayed type hypersensitivity against the implicated antigen.
131
What are the morphological features of hypersensitivity pneumonitis?
Histologic changes are centered on bronchioles.
1. Interstitial pneumonitis consisting primarily of lymphocytes, plasma cells and macrophages.
2. Non caseating granulomas in 66%.
3. Interstitial fibrosis, honeycombing, and obliterative bronchiolitis (late stages).
4. In more than half, there is intra alveolar infiltrate.
132
What are the clinical features of hypersensitivity pneumonitis?
Following the inhalation of antigenic dust :
1. Recurring episodes of fever.
2. Dyspnea
3. Cough
4. Leukocytosis
5. Symptoms appear 4-6 hours after exposure.
6. In continuous exposure - progressive respiratory failure, dyspnea and cyanosis, decrease in total lung capacity and compliance.
133
In what categories is pulmonary eosinophilia divided into?
1. Acute eosinophilic pneumonia with respiratory failure.
2. Simple pulmonary eosinophilia (Löffler syndrome).
3. Tropical eosinophilia, caused by infection with microfilarie
4. Secondary eosinophilia
5. Idiopathic chronic eosinophilic pneumonia
134
What happens in acute eosinophilic pneumonia?
1. Unknown cause
2. Rapid onset with fever
3. Dyspnea
4. Hypoxemic respiratory failure
5. Diffuse infiltrates
135
What happens in simple pulmonary eosinophilia?
1. Transient pulmonary lesions
2. Eosinophilia in the blood
3. Benign clinical course
4. Thickening of alveolar septa by an infiltrate composed of eosinophils and occasional interspersed giant cells - no necrosis + vasculitis + fibrosis.
136
What happens in chronic eosinophilic pneumonia?
1. Focal areas of cellular consolidation of the lung substance in the periphery of the lung fields.
2. Heavy aggregates of lymphocytes and eosinophils within both the septal walls and the alveolar spaces.
3. High fever
4. Night sweats
5. Dyspnea
137
What are the morphological features of desquamative interstitial pneumonia?
1. Accumulation of large number of macrophages with abundant cytoplasm containing dusty brown pigment (smokers' macrophages).
2. Finely granular iron may be seen into the cytoplasm.
3. Some may contain lamellar bodies (composed of surfactant).
4. Thickened alveolar septa - inflammatory filtrate.
5. Mild interstitial fibrosis.
6. Emphysema is often present.
138
In what patients is pulmonary embolism as common complication?
1. With cardiac disease
2. Cancer
3. Immobilization for several weeks (high risk those with hip fracture).
4. Hypercoagulable states (primary or secondary)
139
What are the two main pathophysiologic consequences of pulmonary embolism?
1. Respiratory compromise due to the non perfumed, though ventilated segment.
2. Hemodynamic compromise due to increased resistance.
140
What percentage of the emboli can actually cause infarction?
10%
141
How can the pulmonary embolus be distinguished from a post mortem clot?
By the lines of Zahn.
142
What are the morphological features of the pulmonary infarct?
1. Hemorrhagic
2. Red-blue area in the early stages.
3. Fibrinous exudate in the pleural surface.
4. 48h - lysis of RBCS - paler, red-brown as hemosiderin produced.
5. Fibrous replacement with time - gray-white peripheral zone.
143
What is histologically the diagnostic feature of acute pulmonary infarction?
Ischemic necrosis of the lung substance within the area of hemorrhage, affecting the alveolar walls, bronchioles and vessels.
144
What are the symptoms of a patient that has survived pulmonary embolism?
If it was a sizable embolus :
1. Severe chest pain
2. Dyspnea
3. Shock
4. Fever
5. Increased lactate dehydrogenase
145
How is the diagnosis of pulmonary embolism made?
With spiral computed tomographic angiography.
146
When it is said that pulmonary hypertension has occured?
1. When mean pulmonary pressure reaches 1/4 of systemic levels.
147
What is the clinical classification of PH ?
1. Pulmonary arterial hypertension
2. PH with left heart disease
3. PH associated with lung diseases and/or hypoxia
4. PH due to chronic thrombotic and/or embolic disease
5. Miscellaneous PH
148
With what conditions is PH often associated with?
1. Chronic obstructive of interstitial lung diseases
2. Antecedent congenital or acquired heart disease
3. Recurrent thromboemboli
4. Connective tissue diseases
5. Obstructive sleep apnea
149
What are the uncommon types of PH?
1. Idiopathic pulmonary arterial hypertension
| 2. Familial pulmonary arterial hypertension (AD - incomplete penetrance
150
How is familial PH caused?
By mutations in the bone morphogenetic protein receptor 2 (BMPR2) - TGF-β superfamily.
151
Is only BMPR2 mutation enough to occur PH?
No, it requires modifiers genes + environmental triggers (two-hit model) to occur PH.
152
What is the common morphological feature of all forms of PH ?
Medial hypertrophy of muscular and elastic arteries + atheromas of pulmonary artery + right ventricular hypertrophy.
153
When the signs and symptoms of the PH become evident?
Only with advanced disease.
154
What are the presenting features in cases of idiopathic PH ?
1. Dyspnea
2. Fatigue
3. Some patients with chest pain of anginal type.
155
What are the pulmonary hemorrhage syndromes?
1. Goodpasture syndrome
2. Idiopathic pulmonary hemosiderosis
3. Vasculitis-associated hemorrhage (in conditions such as hypersensitivity angiitis, wegener granulomatosis, SLE)
156
What happens in Goodpasture syndrome?
Uncommon autoimmune disease in which kidney and lung injury are caused by circulating antibodies against the noncollagenous domain of tha α3 chain of collagen IV.
157
What are the morphological features of Goodpasture syndrome?
1. Heavy lungs with red-brown consolidation.
2. Focal necrosis of alveolar walls associated with intra-alveolar hemorrhages.
3. Hemosiderin-laden macrophages
4. In the kidneys - focal proliferative glomerulonephritis.
158
What are the clinical features of Goodpasture syndrome?
1. Begin with respiratory symptoms and hemoptysis.
2. Rapidly progressive renal failure - glomerulonephritis.
3. Death by uremia (common)
4. Improvement by intensive plasmapheresis.
159
What are the factors that can interfere with the local defense mechanisms of the lung?
1. Loss or suppression of the cough reflex
2. Injury to the mucociliary apparatus
3. Accumulation of secretions
4. Interference with the phagocytic/bactericidal action of alveolar macrophages.
5. Pulmonary congestion / edema
160
Mention three important point in pulmonary infections that are usually forgotten.
1. One pneumonia sometimes predisposes to another (especially in debilitated patients).
2. Although the portal is the respiratory tract, hematogenous spread can occur.
3. Many patients (chronic diseases) acquire terminal pneumonia so while hospitalized (nosocomial infection).
161
What bacteria/viruses can cause community-acquired acute pneumonia?
1. Streptococcus pneumoniae
2. Haemophilus influenza
3. Moraxella catarrhalis
4. Staphylococcus aureus
5. Legionella pneumophila
6. Enterobacteriaceae (Klebsiella pneumoniae)
7. Pseudomonas spp.
162
What is the most common cause of community-acquired acute pneumonia ?
Streptococcus pneumoniae
163
In what forms is haemophilus influenza presented?
1. Encapsulated (5%)
| 2. Unencapsulated (95%)
164
What antibodies are degraded by H. influenza?
IgA - major in the airways.
165
How H. influenza prevents opsonization?
With the presence of the capsule.
166
With what consequences is staphylococcus aureus (pneumonia) associated with?
1. Lung abscess
2. Empyema
3. Endocarditis (for intravenous drug users)
167
What is the most frequent cause of gram-negative bacterial pneumonia?
Klebsiella pneumoniae
168
What are the two patterns of anatomic distribution in bacterial pneumonia?
1. Lobular bronchopneumonia
| 2. Lobar pneumonia
169
What are the four stages of lobar pneumonia?
1. Congestion
2. Red hepatization
3. Gray hepatization
4. Resolution
170
What are the major complications of pneumonia?
1. Abscess formation
2. Empyema - spread of infection in the pleural cavity, causing the intrapleural fibrinosuppurative reaction known as Empyema.
3. Bacteremic dissemination - heart valves, pericardium, brain, spleen, kidneys etc.
171
What are the major symptoms of community-acquired acute pneumonia?
1. Abrupt onset of high fever
2. Shaking chills
3. Cough productive of mucopurulent sputum (occasional hemoptysis)
4. When fibrinosuppurative pleuritis - pleuritic pain and pleural friction rub.
172
What is the most common agent that causes community acquired atypical pneumonias?
Mycoplasma pneumoniae
173
What is the common pathogenetic mechanism in community-acquired atypical pneumonias?
Attachment of the organisms to the upper respiratory tract epithelium followed by necrosis and inflammation.
174
What are the morphological patterns that all causal agents produce in community-acquired atypical pneumonias?
1. Lung involvement - patchy of whole lobes bilaterally/unilaterally.
2. Red blue congested affected areas.
3. Smooth pleura
4. Predominant - interstitial nature of inflammation - within the alveolar walls.
175
What are the main morphological features of viral upper respiratory tract infections (community acquired atypical pneumonias)?
1. Mucosal hyperemia
2. Swelling with a predominantly lymphomonocytic and plasmacytic infiltration of the submucosal accompanied by overproduction of mucus secretions.
176
What are the presenting symptoms of SARS?
After 2-10 days :
1. Dry cough
2. Malaise
3. Myalgias
4. Fever
5. Chills
177
What is the cause of SARS?
Coronavirus
178
In what patients is hospital-acquired pneumonia more common?
1. Severe underlying disease
2. Immunoseppresion
3. Prolonged antibiotic therapy
4. Invasive access devices (catheter)
179
What are the most common agents in hospital-acquired pneumonia?
1. Gram-negative rods
| 2. S. Aureus
180
What describes the term pulmonary abscess?
A local suppurative process within the lung, characterized by necrosis of lung tissue.
181
How are the causative organisms introduced in lung abscess?
1. Aspiration of infected material.
2. Antecedent primary lung infection
3. Septic embolism
4. Neoplasia
5. Miscellaneous - direct traumatic penetrations of the lung.
182
What are the main morphological characteristics of abscesses?
1. Diameter : mm - 5/6cm
2. Single/ multiple , anywhere.
3. Abscess cavity filled with suppurative debris.
4. Cardinal histologic change - suppurative destruction of the lung parenchyma within the central area of cavitation.
5. Continued infections - gangrene of the lung.
183
What are the clinical manifestations of lung abscess?
1. Cough
2. Fever
3. Copious amounts of foul-smelling purulent/sanguineous sputum.
4. Chest pain and weight loss are common.
184
What is chronic pneumonia?
A localized lesion in the immunocompetent patient, with or without regional lymph involvement. Granulomatous inflammation caused mainly by bacteria.
185
Why histoplasmosis, blastomycosis and coccidioidomycosis are grouped together?
1. Granulomatous diseases of the lung that resemble tuberculosis.
2. Caused by fungi with common features.
3. Each fungus is geographic.
186
What is the clinical presentation of histoplasmosis?
1. Self-limited and often latent primary pulmonary involvement - result in coin lesions.
2. Chronic progressive secondary lung disease - localized in the apices + cough, fever, night sweats.
3. Localized lesions in extrapulmonary sites (mediastinum, adrenals, liver, meninges).
4. Widely disseminated disease in immunocompromised patients.
187
What are the three clinical forms of blastomycosis?
1. Pulmonary blastomycosis
2. Disseminated blastomycosis
3. Rare primary cutaneous form
188
How is pulmonary blastomycosis present?
1. Abrupt illness with cough
2. Headache
3. Chest pain
4. Weight loss
5. Fever
6. Anorexia
7. Abdominal pain
8. Night sweats
9. Chills
189
What are the three general principles of HIV-associated pulmonary disease?
1. Bacterial lower respiratory tract infection caused by the usual pathogens is one the most serious pulmonary disorders in HIV infection.
2. Not all pulmonary infiltrates in HIV-infected individuals are infectious in etiology.
3. The CD4+ T cell count can define the risk of infection with specific organisms.
190
How is lung cancer for practical purposes divided?
1. Small cell carcinoma
| 2. Non small cell carcinoma
191
What are the three types of precursor lesions that are recognized ?
1. Squamous dysplasia and carcinoma in situ.
2. Atypical adenomatous hyperplasia.
3. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia.
192
What are tha major categories of lung cancer?
1. Adenocarcinoma (m: 37% , f:47%)
2. Squamous cell carcinoma (32%, 25%)
3. Small cell carcinoma (14%, 18%)
4. Large cell carcinoma (18%, 10%)
193
What lung cancers have strong relationship with smoking?
1. Squamous cell carcinoma
| 2. Small cell carcinoma
194
Where do lung carcinomas most often arise?
In and about the hilus of the lung.
195
How is distant spread of lung carcinoma occur?
Through both lymphatic and hematogenous pathways.
196
In contrast to other lung tumors, which one metastasizes outside the thorax late?
Squamous cell carcinoma
197
Where are the principal sites of metastasis?
1. Adrenals (more than 50%)
2. Liver (20-50%)
3. Brain (20%)
4. Bone (20%)
198
What is the most common type of lung cancer in women and nonsmokers?
Adenocarcinoma
199
What mutations occur primarily in adenocarcinoma ?
KRAS mutations
200
Where occurs bronchioalveolar carcinoma? What percentage of all lung cancers represents?
1. Occurs in the pulmonary parenchyma in the terminal bronchioalveolar regions.
2. 1-9%
201
How does adenocarcinoma of the lung occur?
From atypical adenomatous hyperplasia progressing to bronchioalveolar carcinoma, which then transforms into invasive adenocarcinoma. (It is proposed)
202
How is histologically squamous cell carcinoma characterized?
1. Keratinization
| 2. Intercellular brigdes
203
What mutations show the highest frequency in squamous cell carcinoma?
p53 mutations
204
What is the distinctive cell type that is presented in small cell carcinoma?
1. Relatively small
2. With scant cytoplasm
3. Ill defined cell borders
4. Finely granular nuclear chromatin
5. Absent or inconspicuous nucleoli
205
What neuroendocrine markers are present in small cell carcinoma?
1. Chromogranin
2. Synaptophysin
3. CD57
4. PTH-like products
206
What mutation usually occur in small cell carcinomas?
p53 and RB1 (50-80% and 80-100%) respectively. Also BCL2 high in 90%.
207
Mention the principal changes that occur with lung carcinomas distal to the point of bronchial involvement.
1. Partial obstruction may cause marked focal emphysema.
2. Total obstruction may lead to atelectasis.
3. Severe suppurative or ulcerative bronchitis or bronchiectasis occur.
4. Pulmonary abscesses.
5. Superior vena cava syndrome.
6. Pericarditis or pleuritis
208
What are the major presenting complaints in patients with lung cancer?
1. Cough (75%)
2. Weight loss (40%)
3. Chest pain (40%)
4. Dyspnea (20%)
209
Lung cancer can be associated with several para neoplastic syndromes. Mention some of them.
1. Inappropriate ADH secretion
2. ACTH secretion
3. PTH, PTH-rP, PGE2, some cytokines - hypercalcemia
4. Calcitonin - hypocalcemia
5. Gonadotropins - gynecomastia
6. Serotonin and bradykinin - with carcinoid syndrome
210
What lung tumors produce mainly ADH and ACTH ?
Small cell carcinoma
211
What lung tumor causes hypercalcemia?
Squamous cell carcinoma
212
What is called the acinus?
The part of the lung distal to the terminal bronchiole.
213
What causes principally resorption atelectasis?
Excessive secretions (mucus plugs) or exudates within the smaller bronchi.
214
Where is resorption atelectasis most commonly found?
1. Bronchial asthma
2. Chronic bronchitis
3. Bronchiectasis
4. Post-operative states
5. Aspiration of foreign bodies
6. Rarely, neoplasms
215
What is the major characteristic that defines Acute Lung Injury (ALI) - also called non cardiogenic pulmonary edema?
The ABRUPT onset of significant HYPOXEMIA and diffuse pulmonary infiltrates in the absence of cardiac failure.
216
To what refers ARDS?
To SEVERE acute lung injury (ALI).
217
What is the major histologic manifestation of ALI and ARDS?
Diffuse ALVEOLAR damage.
218
How do we call ALI in the absence of any etiology ?
ACUTE INTERSTITIAL PNEUMONIA (AIP)
219
What are the major morphologic features in acute stage of ALI?
1. LUNGS : firm, red, boggy + congestion, interstitial and intra-alveolar edema + inflammation + DIFFUSE ALVEOLAR DAMAGE.
2. ALVEOLAR WALLS : lined with hyaline membranes consisting of fibrin-rich edema fluid.
220
What is called the acinus?
The part of the lung distal to the terminal bronchiole.
221
What causes principally resorption atelectasis?
Excessive secretions (mucus plugs) or exudates within the smaller bronchi.
222
Where is resorption atelectasis most commonly found?
1. Bronchial asthma
2. Chronic bronchitis
3. Bronchiectasis
4. Post-operative states
5. Aspiration of foreign bodies
6. Rarely, neoplasms
223
What is the major characteristic that defines Acute Lung Injury (ALI) - also called non cardiogenic pulmonary edema?
The ABRUPT onset of significant HYPOXEMIA and diffuse pulmonary infiltrates in the absence of cardiac failure.
224
To what refers ARDS?
To SEVERE acute lung injury (ALI).
225
What is the major histologic manifestation of ALI and ARDS?
Diffuse ALVEOLAR damage.
226
How do we call ALI in the absence of any etiology ?
ACUTE INTERSTITIAL PNEUMONIA (AIP)
227
What are the major morphologic features in acute stage of ALI?
1. LUNGS : firm, red, boggy + congestion, interstitial and intra-alveolar edema + inflammation + DIFFUSE ALVEOLAR DAMAGE.
2. ALVEOLAR WALLS : lined with hyaline membranes consisting of fibrin-rich edema fluid.
228
How quickly does the inflammation process begin in ARDS ?
As early as 30minutes after an acute insult - increased synthesis of IL-8.
229
What determines the degree of tissue injury and clinical severity in ALI/ARDS?
The balance between protective and destructive factors.
230
In respect to pulmonary function, what is observed in patients with diffuse OBSTRUCTIVE disorders?
Pulmonary function tests show decreased maximal airflow rates during forced expiration - usually measured by FEV at 1sec.
231
Is there an overlap between asthma, emphysema, and chronic bronchitis?
Yes, and it is substantial.
232
Where is distal acinar (paraseptal) emphysema more striking?
1. Adjacently to the PLEURA.
2. Along the lobular connective tissue septa.
3. At the margins of the lobules.
4. More severe in the UPPER half of the lungs (SMOKE GOES UP).
233
Is there any relationship between distal acinar (paraseptal) emphysema and spontaneous pneumothorax?
Yes - it probably underlies many cases of spontaneous pneumothorax in young adults.
234
What percentage of patients with emphysema has a1-antitrypsin deficiency?
1%
235
What is the role of nicotine in the accumulation of neutrophils and macrophages?
It acts as a chemoattractant.
236
What is the "functional" deficiency of α1-antitrypsin?
A secondary consequence of OXIDATIVE INJURY is inactivation of native antiproteases.
237
Mention one perplexing feature of COPD.
Smoldering inflammation and slow progressive destruction of the lung parenchyma often continues for decades AFTER cessation of smoking.
238
What is the key to diagnosis of emphysema?
Expiratory airflow limitation, best measured through spirometry.
239
What are the treatment options for emphysema patients?
1. Bronchodilators
2. Steroids
3. Bullectomy
4. Lung volume reduction surgery + lung transplantation.
240
What does the term "compensatory hyperinflation" mean?
Used to designate dilation of the alveoli but NOT destruction of septal walls in response to LOSS of lung substance elsewhere!
241
Mention one example of compensatory hyperinflation.
Hyperexpansion of the residual lung parenchyma that follows surgical removal of a diseased lung or lobe.
242
What happens in obstructive overinflation?
The lung EXPANDS because air is trapped within it.
243
Mention a common cause of obstructive overinflation.
Subtotal obstruction by a tumor or foreign object.
244
Under what conditions does obstructive overinflation occur?
1. Because of ball-valve action of the obstructive agent - air enters on inspiration but cannot leave on expiration.
2. Because the bronchus may be totally obstructed but ventilation through COLLATERALS (pores of Kohn + canals of Lambert) may bring in air from behind the obstruction.
245
What happens in bullous emphysema?
A descriptive term for large subpleural blebs or bullae.
| Localized accentuations of emphysema - near the APEX - sometimes in relation to old tuberculous scarring.
246
What happens in interstitial emphysema?
The ENTRANCE OF AIR into the connective tissue stroma of the lung, mediastinum, or subcutaneous tissue.
247
What is the cardinal symptom in chronic bronchitis ?
Persistent cough productive of sputum.
248
What is the clinical course in the passage of time in patients with chronic bronchitis?
Other elements of COPD appear :
1. Hypercapnia
2. Hypoxemia
3. Mild cyanosis ("blue bloaters")
249
Where does long standing severe chronic bronchitis lead to?
Cor pulmonale with cardiac failure.
250
What are the hallmarks of asthma?
1. Increased airway responsiveness to a variety of stimuli.
2. Resulting in EPISODIC bronchoconstriction.
3. Inflammation of the BRONCHIAL WALLS.
4. Increased MUCUS SECRETION.
251
What are the common triggers in asthma?
1. Respiratory infections (especially VIRAL infections).
2. Environmental exposure to irritants (smoke, fumes).
3. Cold air
4. Stress
5. Excercise
252
Mention the main differing patterns of airway inflammation?
1. Eosinophilic
2. Neutrophilic
3. Mixed inflammatory
4. Pauci-granulocytic asthma
253
What is the postulated mechanism about how virus-induced inflammation causes asthma?
It lowers the threshold of the subepithelial vagal receptors to irritants.
254
In what patients is drug-induced asthma common?
In individuals with :
1. Recurrent rhinitis
2. Nasal polyps
255
What are the underlying mechanisms in occupational asthma?
They vary according to stimulus :
1. Include type I reactions
2. Direct liberation of bronchoconstrictor substances
3. Hypersensitivity responses of unknown origin
256
What is the role of the eosinophilic major basic protein in the pathogenetic events of asthma?
It causes EPITHELIAL DAMAGE and more airway CONSTRICTION.
257
What happens in status asthmaticus?
Most SEVERE form :
The severe acute paroxysm persists for days and even weeks - so EXTREME airflow obstruction as to cause severe CYANOSIS and even DEATH.
258
What helps the clinical diagnosis of asthma?
1. Demonstration of an increase in airflow obstruction (from baseline levels).
2. Difficulty in EXHALATION.
3. Elevated EOSINOPHIL count.
4. Curschmann spirals.
5. Charcot-Leyden crystals in the sputum (particularly in atopic asthma).
259
What is necessary for bronchiectasis to be considered?
The dilation must be PERMANENT.
| Viral/Bacterial pneumonia often causes REVERSIBLE bronchial dilation.
260
Describe briefly what happens in primary ciliary dyskinesia.
1. Autosomal recessive syndrome.
2. 1/15.000-40.000
3. Recurrent infections due to poorly functioning cilia.
4. Absence or shortening of DYNEIN arms.
5. Approx. half the patients present with KARTAGENER syndrome.
6. Also infertile as a result of sperm dysmotility.
261
What affects usually bronchiectasis?
Usually affects the lower lobes bilaterally - vertical air passages.
Most severe in the DISTAL bronchi and bronchioles.
262
What bacteria usually infect the lung in bronchiectasis?
A mixed flora can be cultured from the involved bronchi :
1. Staphylococci
2. Streptococci
3. Pneumococci
4. Enteric organisms
5. Microaerophilic bacteria : H.influenza + P.aeruginosa.
263
What is called the acinus?
The part of the lung distal to the terminal bronchiole.
264
What causes principally resorption atelectasis?
Excessive secretions (mucus plugs) or exudates within the smaller bronchi.
265
Where is resorption atelectasis most commonly found?
1. Bronchial asthma
2. Chronic bronchitis
3. Bronchiectasis
4. Post-operative states
5. Aspiration of foreign bodies
6. Rarely, neoplasms
266
What is the major characteristic that defines Acute Lung Injury (ALI) - also called non cardiogenic pulmonary edema?
The ABRUPT onset of significant HYPOXEMIA and diffuse pulmonary infiltrates in the absence of cardiac failure.
267
To what refers ARDS?
To SEVERE acute lung injury (ALI).
268
What is the major histologic manifestation of ALI and ARDS?
Diffuse ALVEOLAR damage.
269
How do we call ALI in the absence of any etiology ?
ACUTE INTERSTITIAL PNEUMONIA (AIP)
270
What are the major morphologic features in acute stage of ALI?
1. LUNGS : firm, red, boggy + congestion, interstitial and intra-alveolar edema + inflammation + DIFFUSE ALVEOLAR DAMAGE.
2. ALVEOLAR WALLS : lined with hyaline membranes consisting of fibrin-rich edema fluid.
271
What are the components of alveolar hyaline membranes?
Fibrin-rich EDEMA fluid mixed with the cytoplasmic and lipid remnants of necrotic epithelial cells.
272
In individuals with diffuse obstructive disorders, what do pulmonary function tests show?
Decreased maximal airflow rates during forced expiration, usually measured by forced expiratory volume at 1 second.
273
Is there an overlap between emphysema, chronic bronchitis, and asthma?
Yes, and in recent studies it is found to be substantial.
274
Where is distal acinar (paraseptal) emphysema most striking?
It is more striking adjacent to the PLEURA along the lobular connective tissue septa - at the margins of the lobules.
IT IS MORE SEVERE IN THE UPPER HALF OF THE LUNGS!
275
What type of emphysema probably underlies many cases of spontaneous pneumothorax in young adults?
Distal acinar (paraseptal) emphysema.
276
How many patients with emphysema have α1-antitrypsin deficiency?
1%
277
What is functional α1-antitrypsin deficiency?
A secondary consequence of oxidative injury is inactivation of native anti-proteases, resulting in FUNCTIONAL AAD.
278
Mention one of the perplexing features of COPD?
Smoldering inflammation and slow progressive destruction of the lung parenchyma often continue for decades after cessation of smoking.
279
Morphologically, where are apical blebs or bullae more characteristically found?
1. In IRREGULAR emphysema secondary to scarring.
| 2. In DISTAL ACINAR emphysema.
280
What is the key to the diagnosis of emphysema?
Expiratory airflow limitation, best measured through spirometry, is the key to diagnosis.
281
What are the treatment options in emphysema?
1. Bronchodilators
2. Steroids
3. Bullectomy
4. Lung volume reduction surgery and lung transplantation.
282
What is the usage of the term "compensatory hyperinflation" ?
To designate dilation of alveoli but NOT destruction of septal walls in response to loss of substance elsewhere.
Best example : HYPEREXPANSION of the residual lung parenchyma that follows surgical removal of a diseased lung or lobe.
283
What happens in obstructive overinflation?
The lung expands because air is trapped within it.
284
What is a common cause of obstructive overinflation?
Subtotal obstruction by a tumor or foreign object.
285
Why does overinflation in obstructive lesions occur ?
1. Because of a ball-valve action of the obstructive agent, so that air enters on aspiration but cannot leave on expiration.
2. Because the bronchus may be totally obstructed but ventilation through COLLATERALS may bring in air from behind the obstruction.
286
What is bullous emphysema?
A descriptive term for large subpleural blebs or bullae that can occur in ANY form of emphysema.
NEAR THE APEX.
287
What happens in interstitial emphysema?
The entrance of air into the connective tissue stroma of the lung, mediastinum, or subcutaneous tissue is called interstitial emphysema.
288
When does alveolar tear usually occur? (Causing interstitial emphysema).
When there is a combination of coughing plus some bronchiolar obstruction, producing sharply increased pressures within the alveolar sacs.
289
How do the neutrophils stimulate mucus hypersecretion in chronic bronchitis?
By releasing of proteases :
1. Elastase
2. Cathepsin
3. MMPs
290
Why do these metaplastic changes in chronic bronchitis happens?
It is through that both the SUBMUCOSAL GLAND HYPERTROPHY and the increase in goblet cells are protective metaplastic reactions against tobacco smoke or other pollutants.
291
Although mucus hypersecretion in large airways is the cause of sputum overproduction, what it is now thought about the accompanied ALTERATIONS IN THE SMALL AIRWAYS?
These alterations can result in physiologically important and early manifestations of chronic airway obstruction.
292
How does cigarette smoke predispose to infection?
1. It interferes with CILIARY ACTION of the respiratory epithelium.
2. It may cause direct damage to the AIRWAY epithelium.
3. It INHIBITS the activity of bronchial and alveolar leukocytes to clear bacteria.
293
What are the cardinal symptoms of chronic bronchitis?
A persistent cough productive of sputum.
| For MANY YEARS no other respiratory functional impairment is present, but EVENTUALLY, DYSPNEA on exertion develops.
294
What occurs with the passage of time in chronic bronchitis?
Other features of COPD may appear :
1. Hypercapnia
2. Hypoxemia
3. Mild cyanosis ("blue bloaters")
295
What are the hallmarks of asthma?
1. Increased airway responsiveness to a variety of stimuli - resulting in episodic bronchoconstriction.
2. Inflammation of the bronchial walls.
3. Increased mucus secretion.
296
What is status asthmaticus?
A state of unremitting asthma attacks, that proves fatal : usually such patients have a long history of asthma.
297
What can trigger the episodes of bronchospasm in asthma (atopic and non atopic)?
1. Respiratory infections (VIRAL infections).
2. Environmental irritants (smoke, fumes)
3. Cold air
4. Stress
5. Excercise
298
What are the differing patterns of airway inflammation that are seen in asthma?
1. Eosinophilic
2. Neutrophilic
3. Mixed inflammatory
4. Pauci-granulocytic
299
What is the classification of asthma according to the agents or events that trigger bronchoconstriction?
1. Seasonal
2. Exercise-induced
3. Drug-induced (aspirin)
4. Occupational
5. Asthmatic bronchitis
300
What is thought about the role of viral infections in asthma?
Virus-induced inflammation of the respiratory mucosa LOWERS the threshold of the subepithelial vagal receptors to irritants.
301
Where does aspirin-induced asthma occur?
1. In individuals with recurrent rhinitis.
| 2. With nasal polyps.
302
What are the underlying mechanisms in occupational asthma?
VARY according to stimulus and include :
1. Type I reactions.
2. Direct liberation of bronchoconstrictor substances.
3. Hypersensitivity responses of unknown origin.
303
What is the role of major basic protein in asthma?
The major basic protein of eosinophils causes epithelial damage and MORE airway constriction.
304
What are the Curschmann spirals?
The mucus plugs in asthma contain WHORLS OF SHED EPITHELIUM, which give rise to Curschmann spirals.
305
How do the Curschmann spirals result?
Either from mucus plugging in subepithelial mucus gland DUCTS which later become extruded OR from plugs in broncioles.
306
Describe what happens during airway remodeling in asthma.
1. Overall thickening of airway wall.
2. Sub-basement membrane fibrosis (due to deposition of type I and III collagen beneath the classic basement membrane).
3. Increased vascularity.
4. An increase in size of the SUBMUCOSAL GLANDS and mucus metaplasia of airway epithelial cells.
5. Hypertrophy/hyperplasia of the bronchial wall muscle.
307
What happens in status asthmaticus?
The severe acute paroxysm persists for days and even WEEKS and under these circumstances AIRFLOW OBSTRUCTION might be so extreme as to cause : SEVERE CYANOSIS AND DEATH.
308
What aids the clinical diagnosis in asthma?
1. Increase in airflow obstruction.
2. Difficulty in EXHALATION (prolonged expiration, wheezing).
3. Elevated eosinophil count.
4. Findings in the sputum : eosinophils, Curschmann spirals, Charcot-Leyden crystals.
309
What often accompanies REVERSIBLE bronchodilation ?
Viral and bacterial pneumonia ! BRONCHIECTASIS requires the dilation to be permanent.
310
What happens generally in primary ciliary dyskinesia?
1. Autosomal recessive with variable penetrance.
2. 1/15.000-40.000 births.
3. POORLY FUNCTIONING CILIA - retention of secretions and recurrent infections - lead to BRONCHIECTASIS.
311
What do approx. half the patients with primary cilia dyskinesia have?
Kartagener syndrome.
312
What happens briefly in Kartagener syndrome?
1. Bronchiectasis
2. Sinusitis
3. Situs inversus or partial lateralizing abnormality
313
What aspergillosis is related to asthma?
Allergic bronchopulmonary aspergillosis
314
What sites of the lung does bronchiectasis most commonly affect?
LOWER LOBES BILATERALLY - vertical air passages.
| More severe in the DISTAL BRONCHI and BRONCHIOLES.
315
On the cut surface of the lung, what is the appearance of the transacted dilated bronchi?
They appear as CYSTS filled with MUCOPURULENT secretions.
316
Can pseudostratification of the columnar cells or squamous metaplasia of the epithelium occur in bronchiectasis?
There is DESQUAMATION of the lining epithelium and EXTENSIVE NECROTIZing ULCERATION -
Also : there MAY BE pseudostratification of the columnar cells OR squamous metaplasia of the REMAINING EPITHELIUM.
317
Can we see a lung abscess in bronchiectasis?
Yes : if the NECROSIS completely destroys the bronchial or bronchiolar walls and forms a LUNG ABSCESS.
318
What microbes are contained within the mixed flora of the bronchi in bronchiectasis?
1. Staphylococci
2. Streptococci
3. Pneumococci
4. Enteric organisms
5. Anaerobic
6. Microaerophilic bacteria : Haemophilus influenzae and Pseudomonas Aeruginosa.
319
Are the symptoms of bronchiectasis episodic?
Yes
320
What precipitates the symptoms of bronchiectasis?
Upper respiratory tract infection.
321
What are the general features of a patient with chronic diffuse interstitial (restrictive) disease?
1. Dyspnea
2. Tachypnea
3. End-respiratory crackles
4. Eventual cyanosis, WITHOUT wheezing or other evidence of airway obstruction.
322
What are the classic physiologic features in restrictive lung diseases?
1. Reduction in CO diffusing capacity
2. Reduction in lung volume
3. Reduction in compliance
323
What does chest radiographs show in restrictive lung diseases?
1. Bilateral infiltrative lesions on the form of small nodules.
2. Irregular lines
3. Ground-glass shadows (HENCE the term infiltrative).
324
What is the popular term in Europe for IPF?
Cryptogenic fibrosing alveolitis
325
How is more commonly IPF referred to?
UIP
326
In the pathogenesis of IPF, what is the role of TGF-β1?
It is the driver of the fibrotic process.
It is known to be FIBROGENIC !
It is released from injured type I alveolar epithelial cells.
It favors the TRANSFORMATION of fibroblasts into myofibroblasts and DEPOSITION of collagen and other ECM components.
327
What is the relation between TGF-β1 and telomerase?
TGF-β1 negatively regulates telomerase activity, thus facilitating epithelial cell APOPTOSIS and the cycle of death and repair.
328
What is the main action of caveolin-1?
Acts as an endogenous inhibitor of pulmonary fibrosis by limiting TGF-β1-induced production of ECM and RESTORING alveolar epithelial repair processes.
329
What is honeycomb fibrosis?
The dense fibrosis causes :
1. Destruction of alveolar architecture.
2. Formation of cystic spaces lined by hyperplastic type II pneumocytes or bronchiolar epithelium.
330
In connective tissue diseases, what are the common "forms" of pulmonary involvement?
1. NSIP
2. UIP
3. Vascular sclerosis
4. Organizing pneumonia
5. Bronchiolitis
331
What do smaller particles tend to cause in contrast to larger particles?
Smaller particles : ACUTE LUNG INJURY
Larger particles : FIBROSING COLLAGENOUS PNEUMOCONIOSES - they resist resolution, perista in the lung parenchyma for years.
332
What is the course of the inhaled carbon pigment in the lungs?
1. It is engulfed by alveolar/interstitial macrophages.
2. Then ACCUMULATE in the connective tissue ALONG THE LYMPHATICS.
3. Pleural lymphatics - into organizing lymphoid tissue along the bronchi or in the lung hilus.
333
What is status asthmaticus?
A state of unremitting asthma attacks, that proves fatal : usually such patients have a long history of asthma.
334
What can trigger the episodes of bronchospasm in asthma (atopic and non atopic)?
1. Respiratory infections (VIRAL infections).
2. Environmental irritants (smoke, fumes)
3. Cold air
4. Stress
5. Excercise
335
What are the differing patterns of airway inflammation that are seen in asthma?
1. Eosinophilic
2. Neutrophilic
3. Mixed inflammatory
4. Pauci-granulocytic
336
What is the classification of asthma according to the agents or events that trigger bronchoconstriction?
1. Seasonal
2. Exercise-induced
3. Drug-induced (aspirin)
4. Occupational
5. Asthmatic bronchitis
337
What is thought about the role of viral infections in asthma?
Virus-induced inflammation of the respiratory mucosa LOWERS the threshold of the subepithelial vagal receptors to irritants.
338
Where does aspirin-induced asthma occur?
1. In individuals with recurrent rhinitis.
| 2. With nasal polyps.
339
What are the underlying mechanisms in occupational asthma?
VARY according to stimulus and include :
1. Type I reactions.
2. Direct liberation of bronchoconstrictor substances.
3. Hypersensitivity responses of unknown origin.
340
What is the role of major basic protein in asthma?
The major basic protein of eosinophils causes epithelial damage and MORE airway constriction.
341
What are the Curschmann spirals?
The mucus plugs in asthma contain WHORLS OF SHED EPITHELIUM, which give rise to Curschmann spirals.
342
How do the Curschmann spirals result?
Either from mucus plugging in subepithelial mucus gland DUCTS which later become extruded OR from plugs in broncioles.
343
Describe what happens during airway remodeling in asthma.
1. Overall thickening of airway wall.
2. Sub-basement membrane fibrosis (due to deposition of type I and III collagen beneath the classic basement membrane).
3. Increased vascularity.
4. An increase in size of the SUBMUCOSAL GLANDS and mucus metaplasia of airway epithelial cells.
5. Hypertrophy/hyperplasia of the bronchial wall muscle.
344
What happens in status asthmaticus?
The severe acute paroxysm persists for days and even WEEKS and under these circumstances AIRFLOW OBSTRUCTION might be so extreme as to cause : SEVERE CYANOSIS AND DEATH.
345
What aids the clinical diagnosis in asthma?
1. Increase in airflow obstruction.
2. Difficulty in EXHALATION (prolonged expiration, wheezing).
3. Elevated eosinophil count.
4. Findings in the sputum : eosinophils, Curschmann spirals, Charcot-Leyden crystals.
346
What often accompanies REVERSIBLE bronchodilation ?
Viral and bacterial pneumonia ! BRONCHIECTASIS requires the dilation to be permanent.
347
What happens generally in primary ciliary dyskinesia?
1. Autosomal recessive with variable penetrance.
2. 1/15.000-40.000 births.
3. POORLY FUNCTIONING CILIA - retention of secretions and recurrent infections - lead to BRONCHIECTASIS.
348
What do approx. half the patients with primary cilia dyskinesia have?
Kartagener syndrome.
349
What happens briefly in Kartagener syndrome?
1. Bronchiectasis
2. Sinusitis
3. Situs inversus or partial lateralizing abnormality
350
What aspergillosis is related to asthma?
Allergic bronchopulmonary aspergillosis
351
What sites of the lung does bronchiectasis most commonly affect?
LOWER LOBES BILATERALLY - vertical air passages.
| More severe in the DISTAL BRONCHI and BRONCHIOLES.
352
On the cut surface of the lung, what is the appearance of the transacted dilated bronchi?
They appear as CYSTS filled with MUCOPURULENT secretions.
353
Can pseudostratification of the columnar cells or squamous metaplasia of the epithelium occur in bronchiectasis?
There is DESQUAMATION of the lining epithelium and EXTENSIVE NECROTIZing ULCERATION -
Also : there MAY BE pseudostratification of the columnar cells OR squamous metaplasia of the REMAINING EPITHELIUM.
354
Can we see a lung abscess in bronchiectasis?
Yes : if the NECROSIS completely destroys the bronchial or bronchiolar walls and forms a LUNG ABSCESS.
355
What microbes are contained within the mixed flora of the bronchi in bronchiectasis?
1. Staphylococci
2. Streptococci
3. Pneumococci
4. Enteric organisms
5. Anaerobic
6. Microaerophilic bacteria : Haemophilus influenzae and Pseudomonas Aeruginosa.
356
Are the symptoms of bronchiectasis episodic?
Yes
357
What precipitates the symptoms of bronchiectasis?
Upper respiratory tract infection.
358
What are the general features of a patient with chronic diffuse interstitial (restrictive) disease?
1. Dyspnea
2. Tachypnea
3. End-respiratory crackles
4. Eventual cyanosis, WITHOUT wheezing or other evidence of airway obstruction.
359
What are the classic physiologic features in restrictive lung diseases?
1. Reduction in CO diffusing capacity
2. Reduction in lung volume
3. Reduction in compliance
360
What does chest radiographs show in restrictive lung diseases?
1. Bilateral infiltrative lesions on the form of small nodules.
2. Irregular lines
3. Ground-glass shadows (HENCE the term infiltrative).
361
What is the popular term in Europe for IPF?
Cryptogenic fibrosing alveolitis
362
How is more commonly IPF referred to?
UIP
363
In the pathogenesis of IPF, what is the role of TGF-β1?
It is the driver of the fibrotic process.
It is known to be FIBROGENIC !
It is released from injured type I alveolar epithelial cells.
It favors the TRANSFORMATION of fibroblasts into myofibroblasts and DEPOSITION of collagen and other ECM components.
364
What is the relation between TGF-β1 and telomerase?
TGF-β1 negatively regulates telomerase activity, thus facilitating epithelial cell APOPTOSIS and the cycle of death and repair.
365
What is the main action of caveolin-1?
Acts as an endogenous inhibitor of pulmonary fibrosis by limiting TGF-β1-induced production of ECM and RESTORING alveolar epithelial repair processes.
366
What is honeycomb fibrosis?
The dense fibrosis causes :
1. Destruction of alveolar architecture.
2. Formation of cystic spaces lined by hyperplastic type II pneumocytes or bronchiolar epithelium.
367
In connective tissue diseases, what are the common "forms" of pulmonary involvement?
1. NSIP
2. UIP
3. Vascular sclerosis
4. Organizing pneumonia
5. Bronchiolitis
368
What do smaller particles tend to cause in contrast to larger particles?
Smaller particles : ACUTE LUNG INJURY
Larger particles : FIBROSING COLLAGENOUS PNEUMOCONIOSES - they resist resolution, perista in the lung parenchyma for years.
369
What is the course of the inhaled carbon pigment in the lungs?
1. It is engulfed by alveolar/interstitial macrophages.
2. Then ACCUMULATE in the connective tissue ALONG THE LYMPHATICS.
3. Pleural lymphatics - into organizing lymphoid tissue along the bronchi or in the lung hilus.
370
Simple CWP is characterized by coal macules. What are the main components of these macules?
Carbon-laden macrophages and also small amounts of a delicate network of collagen fibers.
371
What parts of the lung are more frequently involved in simple CWP?
The UPPER lobes and UPPER ZONES of the lower lobes.
| They are located primarily adjacent to respiratory bronchioles - the site of initial dust accumulation.
372
What is centrilobular emphysema?
In the progress of simple CWP :
| DILATION of adjacent alveoli occurs.
373
What form of silica is much more fibrogenic?
Silica occurs in both CRYSTALLINE and AMORPHOUS forms, but crystalline forms (including quartz, crystobalite, and tridymite) is much more fibrogenic.
374
What does silica cause within the macrophages?
Activation and release of mediators.
375
In silicosis, some nodules may undergo central softening and cavitation. What is usually superimposed in these cases?
Tuberculosis or ischemia.
376
What is the most pathogenic form of asbestos?
Amphiboles even though less prevalent, are more pathogenic than chrysotiles - induction of malignant pleural tumor (mesothelioma)
377
Asbestos is a carcinogen that can act as an initiator or a promoter?
BOTH!
378
With what has asbestos a great synergy for lung cancer?
Tobacco smoking.
379
On what does the occurrence of asbestosis depend?
On the interaction of inhaled fibers with lung macrophages and other parenchymal cells.
380
What is the main morphology of asbestosis ?
It is marked by diffuse pulmonary INTERSTITIAL FIBROSIS - indistinguishable from other interstitial fibrosis from other causes - except for the presence of multiple ASBESTOS BODIES.
381
How are asbestos bodies arise?
They arise when macrophages attempt to phagocytose asbestos fibers - iron is presumably derived from phagocyte ferritin.
382
What are the ferruginous bodies?
Other inorganic particulates may become coated with similar iron-protein complexes.
383
How does asbestosis begin?
As FIBROSIS around RESPIRATORY BRONCHIOLES and ALVEOLAR DUCTS and extends to involve adjacent alveolar sacs and alveoli.
384
In contrast to CWP and silicosis, what are the preferred sites of asbestosis?
It begins in the LOWER lobes and SUBPLEURALLY.
385
What is true about the size and number of pleural plaques in asbestosis?
They do NOT correlate with the level of exposure or the time since exposure. They do NOT contain asbestos bodies.
386
Are pleural effusions common with asbestosis?
NO - when they occur, they are usually serous, but may be bloody.
387
Generally, what are the possible side effects of drugs in the lung?
They can cause acute and chronic alterations :
1. In respiratory structure and function.
2. Interstitial fibrosis.
3. Bronchiolitis obliterans
4. Eosinophilic pneumonia
388
Mention 6 main examples of drug-induced pulmonary disease.
1. Bleomycin - Pneumonitis and fibrosis
2. Methotrexate - Hypersensitivity pneumonitis
3. Amiodarone - Pneumonitis and fibrosis
4. Nitrofurantoin - Hypersensitivity pneumonitis
5. Aspirin - bronchospasm.
6. β-blockers - bronchospasm
389
What is acute radiation pneumonitis?
One to six months after fractionated irradiation acute radiation pneumonitis occurs in 10-20% of patients : lymphocytic alveolitis/hypersensitivity pneumonitis.
390
What are the symptoms of acute radiation pneumonitis?
1. Fever
2. Dyspnea
3. Pleural effusion
4. Radiologic infiltrates
391
Besides lung, what other organs occur next in frequency in sarcoidosis ?
Eye and skin lesions.
392
What other disease looks like sarcoidosis?
Berylliosis
393
Is sarcoidosis higher in women?
YES - but generally it varies.
394
What is the importance of TNF in sarcoidosis?
It is a marker of disease activity - because it is released by activated macrophages.
395
On what does the suspicion for the pathogenesis of sarcoidosis fall?
On microbes - several putative microbes have been proposed.
396
What happens in sarcoidosis granulomas with chronicity?
The granulomas may become enclosed within fibrous rims or may eventually be replaced by HYALINE fibrous scars.
397
What are the Schaumann bodies?
In SARCOIDOSIS : Laminated concentrations composed of CALCIUM and PROTEINS.
398
What are the asteroid bodies?
In SARCOIDOSIS : Stellate inclusions - together with the Schaumann bodies are ENCLOZED within giant cells in approx. 60% of granulomas.
399
Are Schaumann and asteroid bodies pathognomonic for sarcoidosis?
No - they can be encountered in other granulomatous diseases. (Tuberculosis).
400
Is there any macroscopic demonstrable alteration in the lungs in sarcoidosis?
Usually NO : in advanced cases the coalescence of granulomas produce small nodules - non caseating, non cavitated consolidations.
401
In the sarcoidosis lung, where are the lesions distributed?
Primarily along the LYMPHATICS, around BRONCHI, and BLOOD VESSELS - although ALVEOLAR lesions are also seen.
402
What is the "goal" of the sarcoidosis lesion in the lung?
There seems to be a strong tendency for lesions to HEAL in the lungs - so varying stages of FIBROSIS + HYALINIZATION are often found.
403
What are the characteristics of the lymph nodes in sarcoidosis?
Nodes are characteristically : ENLARGED + DISCRETE + CALCIFIED.
The TONSILS are affected in 25-30% of cases.
404
How many sarcoidosis cases have spleen involvement?
Microscopically : 75%
| BUT it is enlarged in 20% of cases.
405
How is the liver involved in sarcoidosis?
1. Slightly less often that the spleen.
2. It may also be moderately ENLARGED.
3. Contains scattered granulomas : More in the PORTAL TRIADS than in the lobular parenchyma.
406
What form takes the ocular involvement in sarcoidosis?
1. Iritis
2. Iridocyclitis
3. Corneal opacities
4. Glaucoma
5. Total loss of vision ah occur.
407
What are the major components of Miculicz syndrome?
BILATERAL sarcoidosis of :
| The PAROTID + SUBMAXILLARY + SUBLINGUAL glands.
408
Is there a muscle involvement in sarcoidosis?
Yes - and it is often underdiagnosed, since it may be asymptomatic.
409
Besides the primary sites, where else do we see sarcoid granulomas?
1. Heart
2. Kidneys
3. Central nervous system
4. Endocrine glands (pituitary)
410
What does the term hypersensitivity pneumonitis describe?
A spectrum of immunologically mediated, predominantly INTERSTITIAL lung disorders caused by intense often prolonged exposure to inhaled organic antigens.
411
What attracts the eosinophils in pulmonary eosinophilia ?
Elevated levels of IL-5.
412
What happens in acute eosinophilic pneumonia with respiratory failure?
1. Acute illness of unknown cause.
2. Rapid onset with fever + dyspnea + hypoxemic respiratory failure.
3. Bronchoalveolar lavage fluid contains more than 25% eosinophils.
413
What is thought to represent the 2 ENDS of a spectrum of SMOKING-associated interstitial lung diseases?
Desquamative interstitial pneumonia and respiratory bronchiolitis-associated interstitial lung disease.
414
What is the target group of desquamative interstitial pneumonia?
1. 30-50 years.
2. More common in men than in women (2:1).
3. ALL patients are cigarette smokers.
415
What are the presenting symptoms of desquamative interstitial lung disease?
1. Insidious onset of dyspnea and dry cough over weeks or months, often associated with CLUBBING of digits.
2. Tests : show MILD RESTRICTIVE abnormality with MODERATE reduction of the diffusing capacity of CO2.
416
What is the main characteristic of respiratory bronchiolitis-associated interstitial lung disease?
Common in SMOKERS - Pigmented intraluminal macrophages within 1st- and 2nd- order respiratory bronchioles.
The term is used for those that develop SIGNIFICANT symptoms + abnormal pulmonary symptoms + imaging abnormalities.
417
What is the morphology in respiratory bronchiolitis-associated interstitial lung disease?
1. Respiratory bronchioles + alveolar ducts + peribronchiolar spaces contain : SMOKER'S MACROPHAGES - dusty brown macrophages.
2. Patchy submucosal and peribronchiolar infiltrate of lymphocytes and histiocytes.
3. Centrilobular emphysema is common, but NOT severe.
4. Histologic OVERLAP with DIP.
418
What are the main clinical features of respiratory bronchiolitis-associated interstitial lung disease?
1. Gradual onset of dyspnea and cough (in smokers).
2. 2:1 male predominance.
3. Cessation of smoking usually results in improvement.
419
On what do the pathophysiologic response and clinical significance of pulmonary embolism depend?
1. The EXTENT to which the pulmonary artery is obstructed.
2. The SIZE of the occluded vessel.
3. The NUMBER of emboli.
4. The overall status of the cardiovascular system.
5. The release of vasoactive factors such as TxA2 from platelets that accumulate at the site of the thrombus.
420
What is acute cor pulmonale?
DEATH by ACUTE failure of the right heart. (pulmonary embolism)
421
What is the fate of a small pulmonary embolus?
1. Travel out into the more peripheral vessels - cause HEMORRHAGE or INFARCTION.
2. In patients with adequate CV function, the BRONCHIAL arterial supply can sustain the lung parenchyma.
3. HEMORRHAGES may occur, but there is NO INFARCTION.
422
What percentage of pulmonary emboli actually cause infarction?
10% - the circulation is ALREADY inadequate - patients with heart/lung diseases.
423
Where in the lung does the pulmonary embolus most often occur?
About 75% affect the LOWER lobes - and in more than 50%, multiple lesions occur.
424
What does the term "electromechanical dissociation" mean?
In LARGE pulmonary embolism - the EKG has a rhythm but NO PULSES are palpated because NO BLOOD is entering the pulmonary arterial circulation.
425
What are the major symptoms caused by SMALL emboli?
1. In pulmonary HEMORRHAGES due to small emboli only TRANSIENT chest pain and cough occur.
2. INFARCTS : dyspnea, tachypnea, fever, chest pain, cough, and hemoptysis.
426
What happens in pulmonary emboli after the acute insult?
They often RESOVLE, via CONTRACTION and FIBRINOLYSIS. (particularly in the relative young).
427
What can UNRESOLVED multiple small thrombi lead to?
PULMONARY HYPERTENSION.
428
In a presence of an underlying predisposing condition, what chance do patients have to develop a second embolus?
30%
429
What are the major features of the mechanism of PH?
OBSTRUCTION to the vasculature caused by proliferation of endothelial smooth muscle + intimal cells - accompanied by CONCENTRIC LAMINAR INTIMAL FIBROSIS.
430
What is the pathogenic role of BMPR2 in the PH?
BMPR2 : in vascular smooth muscle, signaling causes inhibition of proliferation and favors APOPTOSIS.
In the ABSENCE of such signaling, increased smooth muscle survival and proliferation may be expected.
431
Is BMPR2 mutations common in PH?
Inactivating germline mutations in the BMPR2 gene are found in :
1. 50% of familial cases of pulmonary arterial hypertension.
2. 25% of sporadic cases.
432
In PH, how does loss of a single allele of the BMPR2 gene lead to complete loss of signaling?
1. The mutation MIGHT act as a DOMINANT NEGATIVE.
| 2. A secondary loss of the normal allele might occur in the VASCULAR wall, thus leading to homozygous loss of BMPR2.
433
What is the target group of idiopathic PH?
WOMEN 20-40 age. (occasionally in young children).
434
What are the major symptoms in PH?
As with ALL forms of hypertension, clinical signs become evident only with advanced disease.
1. Dyspnea
2. Fatigue
3. Angina-like pain
4. Over time : RESPIRATORY DISTRESS, CYANOSIS, RV hypertrophy.
435
What is the prognosis of idiopathic PH?
DEATH ensues within 2-5 years in 80% of patients : decompensated cor pulmonale, often with superimposed THROMBOEMBOLISM + PNEUMONIA.
436
Goodpasture syndrome is an autoimmune disease. What is special about it?
Most cases occur in the TEENS/20s and in contrast to many other autoimmune diseases, there is MALE PREDOMINANCE (also in one study over 89% were active smokers).
437
What is seen in patients with Goodpasture's that aids the diagnosis?
Lesions in the KIDNEYS : Linear deposits of immunoglobulins + complement along the GLOMERULAR BM (even in the few patients WITHOUT renal disease).
438
What characterizes idiopathic pulmonary hemosiderosis?
Rare disorder : INTERMITTENT, DIFFUSE ALVEOLAR HEMORRHAGE.
| Most cases occur in young children.
439
How does idiopathic pulmonary hemosiderosis usually present?
```
Insidious onset of :
1. Productive cough
2. Hemoptysis
3. Anemia
4. Weight loss
associated with diffuse pulmonary infiltrations SIMILAR to Goodpasture's.
```
440
What are the components of the microscopic structure of the alveolar walls? (From blood to air)
1. Capillary endothelium
2. Basement membrane and surrounding interstitial tissue
3. Alveolar epithelium (type I and II pneumocytes)
4. Alveolar macrophages
