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