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45 Cards in this Set
- Front
- Back
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What are the 3 major types of pneumoconiosis that we studied in this block?
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1. Coal worker's pneumoconiosis (CWP)
2. Asbestosis 3. Silicosis |
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What are the pathogenic principles that apply to all pneumoconiosis regardless of the nature of the injurious agent?
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1. The amount of dust in the lungs and airways.
2. The size, shape, and buoyancy of the dust particles 3. The particle solubility and physico-chemical properties 4. The possible additional (synergistic) effects of other airway irritants such as cigarette smoke. |
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What are the three different types of reactions that someone can have to inhaled coal dust?
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1. Anthracosis
2. Simple coal worker's pneumoconiosis (CWP) 3. Progressive massive fibrosis (PMF) |
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Describe anthracosis
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"Fairly innocuous"
Accumulation of coal dust in pulmonary macrophages. Coal miners, city dwellers, tobacco smokers. |
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Describe simple coal worker's pneumoconiosis.
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A condition resulting from the inhalation and deposition of coal dust and the response to such deposition. Severity is related to cumulative exposure.
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What are the hallmarks of CWP?
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The dust macule and the dust nodule.
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c/c the dust macule vs. the dust nodule.
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The dust macule is a centrilobar coal deposit with a stellate outline of macrophages heavily laden with coal dust. NO colligenization is seen.
The dust nodule is also a stellate shaped centrilobular accumulation of dust, but WITH collagenization. |
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The pathogenesis of CWP has much in common with what other pneumonicosis?
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With silicosis.
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The pathogenesis of CWP is due to the release of what?
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Cytokines such as PDGF, TGF-beta, TNF-alpha, etc.
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The advent of PMF may cause what clinical complications?
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Pulmonary hypertension
Cor pulmonale |
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Is CWP associated with cancer?
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No (there is no compelling evidence).
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Define asbestosis.
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Asbestosis is a parenchymal disorder of the lung characterized by slow, progressive pulmonary fibrosis caused by the inhalation of asbestos fibers.
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What are the two different forms of asbestos called?
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The amphiboles (straight, rod-like, stiff, and brittle)
The serpentines (curly, wavy, more flexible) |
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Gross specimens with asbestosis show what findings?
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Fine subpleural fibrosis more prominent at the bases.
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What is especially important about the physical shape of the asbestos fibers?
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The aspect ratio (length to width ratio)
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A microscopic analysis of asbestosis can look similar to what other disease?
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UIP
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Is lung cancer associated with asbestosis?
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Yes.
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What is the most prevalent occupational disease in the world?
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Silicosis.
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What is the hallmark pathological feature of silicosis?
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The silicotic nodule.
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Describe the appearance of the silicotic nodule.
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The nodule contains tiny birefringent silica particles. The nodules are concentrated at the Macklin's dust sumps (lympoid aggregates guarding the mouths of lymphatics of the lung.)
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How does silica cause damage?
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Silica has fibrogenic properties.
Macrophages injest silica --> silicilic acid is produced --> macrophage lyses, releasing cytokines. |
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Symptoms of silicosis?
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Cough
SOB |
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Silicosis: gross presentation
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Lungs shrink
Overlying fibrosis of the pleura |
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Does silicosis cause lung cancer?
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The association between the two is not clear yet, but probably yes.
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What does RADS stand for?
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Reactive Airway dysfunction Syndrome
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Pneumoconiosis: from inorganic or organic dusts?
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Inorganic
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What pneumoconiosis/hypersensitivity pneumonitis is associated with clubbing?
With crackles? With wheezing? |
Clubbing = asbestosis, IPF
Crackles = asbestosis or HSP (generally not with silicosis or CWP) Wheezing = (athsma, HSP, RADS) |
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What pneumoconiosis/hypersensitivity pneumonitis is associated with increased interstitial markings?
Nodular densities? "Eggshell" calcifications of hilar lymph nodes? Pleural plaques |
Interstitial markings = asbestosis, HSP
Nodular densities = silicosis, CWP "Eggshell" calcifications = silicosis Pleural plaques = asbestosis |
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Abrasive blasting. Think what?
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Silicosis
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Wheezing, breathing trouble that increases from Mon to Fri and then gets better over the weekend. Think what?
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Occupational athsma.
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If you see "eggshell" calicifications of hilar lymph nodes on CT scan, do you need a biopsy to confirm your suspicions?
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No, it's silicosis.
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Silicosis: PFTs
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Will show pure restrictive pattern.
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Silicosis: risk of cancer
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Increased risk. Maybe just because you can't see the cancer on a CT scan.
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Silicosis: increased risk of getting what disease?
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3 fold increased risk of Mycobacterial TB infection!
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Asbestosis: PFTs
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Restrictive pattern with a decreased diffusing capacity.
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Asbestosis: hilar/mediastinal lymphadenopathy
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NOT seen
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What is the histopathologic diagnosis of asbestosis?
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The presence of asbestos bodies (transparent fibers coated with iron and protein) in association with IPF that is similar in appearance to UIP
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Mesothelioma: increased risk of TB?
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No.
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What is the only known risk factor for development of malignant mesothelioma?
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Asbestosis
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What are the most common causative agents of occupational asthma (OA)?
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Isocyanates (used in the production of plastics and rubber)
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OA: treatment
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Switch jobs!
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OA: methacholine challenge
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Usually positive.
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What is the definition of RADS?
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A persistent (over 3 months) asthma-like illness (cough, wheeze, dyspnea) after a single exposure to high levels of an irritating vapor, fume, or smoke. Onset of symptoms is usually around 24 hours after exposure.
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RADS: methacholine challenge
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Usually negative.
Note that a positive methacholine test does not rule out RADS |
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RADS: bronchodilators
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Usually not all that helpful. Usually steroids are necessary.
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