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22 Cards in this Set
- Front
- Back
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How are inhaled dusts cleared from the lungs?
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* Deposited dusts are cleared via macrophages and the mucociliary escalator
* Water-soluble stuff dissolves * Macrophages transport insoluble particles to the lymphatic system |
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What are the 4 main types of occupational lung disorders?
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1) Chemical Pneumonitis
2) Occupational Asthma 3) Hypersensitivity Pneumonitis 4) Pneumoconiosis |
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What is the basic pathologic mechanism for Chemical Pneumonitis?
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Chemical Pneumonitis is the direct injury of lung parenchyma by a toxic agent.
* SXS begin w/in HOURS of exposure |
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What is the basic pathologic mechanism for Occupational Asthma?
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Occupational Asthma is the inhalation of an antigen to which the person has been previously sensitized.
* IgE-driven response * Inflammation & Edema of the airway |
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What is the basic pathologic mechanism for Hypersensitivity Pneumonitis?
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Hypersensitivity Pneumonitis is a complex immunologic reaction involving months/years of exposure.
* Slowly progressive * May lead to diffuse interstitial fibrosis * Predominantly mononuclear infiltrate |
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What is the basic pathologic mechanism for Pneumoconiosis?
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Pneumoconiosis follows exposure to inorganic dusts
* Represents overwhelmed cellular response mechanisms * Months/years of exposure before clinically evident disease |
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Where do pneumoconiotic lesions tend to accumulate?
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1) Lymphatic origins
2) Near respiratory bronchioles 3) Beneath the pleura |
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Name two dusts that may induce pulmonary fibrosis.
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* Silicone dust
* Coal Dust * Asbestos |
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What dust does NOT induce pulmonary fibrosis, but is simply a marker of exposure?
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Inhalation of Iron Dust results in an asymptomatic reaction.
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What size particles will penetrate into the alveoli and lodge, causing problems?
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About 1 micron/micrometer.
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Describe the characteristic pathologic features of siderosis.
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Iron accumulates in macules adjacent to respiratory bronchioles – can be visualized as fine nodules
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escribe the characteristic pathologic features of silicosis.
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* Nodular fibrosis in which the nodules are formed of dense, laminated collagen
* Nodules are also found in regional lymph nodes * Nodules are often partially calicified + visible on x-ray * Sometimes developes into progressive fibrosis |
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Describe the characteristic pathologic features of asbestosis.
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* Asbestosis is caused by exposure to fibrous silicates.
* Diffuse interstitial pulmonary fibrosis * Worse in lower lung zones + near pleura |
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What's the difference between "simple" and "complicated" pneumoconioses?
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Simple:
* Nodular fibrosis * Marker for exposure * Some risk of progression Complicated: * Conglomeration of nodules * Symptomatic w/restrictive physiology * May progress to pulmonary fibrosis |
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Describe the natural history of Silicosis.
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Silicosis:
* May be acute, typically over 20 years * 18% crystalline silica dust |
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Describe the natural history of Asbestosis.
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Asbestosis
* 10-25 year latency * High levels of exposure req'd. |
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What are the two types of Asbestos particles? Which is more dangerous?
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* Serpentine
* Amphibole (far more toxic) |
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What's necessary to make the diagnosis of Asbestosis?
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1) Pulmonary Fibrosis
2) Asbestos Particles |
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On radiogram, pulmonary fibrosis looks like what other lesion?
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Pulmonary neoplasm
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How do mesotheliomas appear histologically?
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Mesotheliomas recapitulate all stages of serosal development
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What inhaled particle will really increase the risk of developing a mesothelioma?
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Amphibole Asbestos
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How do mesotheliomas progress?
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The grow and spread across the pleural surfaces.
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