Pneumoconioses Flashcards
Silicosis
- Small rounded opaque and progress to confluent opacities, to progressive massive fibrosis
- Upper lung small rounded nodules
- Increased risk of TB infection
- Restrictive lung disease
- Silica is carcinogenic
Pneumoconiosis
- restrictive lung diseases/ chronic fibrotic occupational lung disease
Dust lung 10-20 years exposure Permanent parenchymal fibrotic change Restrictive lung diseases Eg. Silicosis Asbestosis Coal worker's pneumoconiosis Beryllium Hard metals (cobalt-tungsten carbide)
Coal workers’ pneumoconiosis
- Macule loaded with coal dust
- Less fibrogenic than silica
Asbestos diseases
- Asbestosis (remember! This refers to the pneumoconiosis)
- Benign pleural effusion (1st manifestation of asbestos exposure after about 10 years of exposure)
- Pleural plaques
- Lung cancer
- Mesothelioma
Asbestos
- Serpentine (curly fibers) (chrysotile) - most in use ( 95%)
- Amphibole ( needle like) - more carcinogenic
Latency - at least 20 years
Asbestosis chest x- ray
Small irregular or linear opacities, fibrosis, esp. at the base of the lung
(Compare to silicosis - small rounded opacities mainly in upper lobes)
Asbestos pathology
Asbestos body
= protein coated fiber which contains iron (ferruginous body)
- only pathological feature unique to asbestosis
Bilateral Upper lung small rounded nodules in x-ray
Silicosis
Bilateral linear fibrotic changes in the lower lobe
Asbestosis
Asbestos + tobacco
- Increases susceptibility for asbestosis
- Increases risk for bronchogenic cancer
- Increased risk for cancer of esophagus, oropharynx and larynx among smokers
(Not for mesothelioma)
Synergistic risk of asbestos and smoking for lung cancer
Non-smoker, non-asbestos exposure: RR = 1 (ref)
Asbestos workers: RR = 5.2
Smokers: RR = 10.8
Smokers+asbestos: RR = 53.2
Egg shell calcification on x-Ray
Silicosis
- silica can be transported by macrophages via pulmonary lymphatics to the hilar nodes, that appear as “egg shell calcifications” on x- ray
Fibrosis and small rounded opacities without hilar node calcification on x-ray?
Coal worker’s pneumoconiosis
Non-caseating granulomatous lesions in the lungs
Beryllium disease
Sarcoidosis
Beryllium lung disease CXR
Upper to middle love interstitial infiltrates, hilar adenopathy
Which of the dusts causes pulmonary fibrosis, rather than simple pneumoconiosis?
Bagasse