Pneumoconiosis = accumulation of (‘inorganic’) dust in the lungs and the reaction of the tissue to its presence.
- Reflects the deposition of coal dust in the lung.
- CXR = micronodular shadowing
Categories of simple pneumoconiosis:
- 1. Small round opacities definitely present but few in number
- 2. Small round opacities numerous but normal lung markings still visible
- 3. Small round opacities very numerous and normal lung markings partly or totally obscured
Simple pneumoconiosis may lead to the development of progressive massive fibrosis (PMF). PMF occurs in 7% of category 2 and 30% with category 3
Progressive massive fibrosis:
- Develop round fibrotic masses several centimetres in diameter
- Usually upper lobe
- Necrotic central cavities
- Antinuclear antibodies and rheumatoid factor present (ANA and RhF +ve) – pt may well have scleroderma/RA.
Apical destruction and disruption of the lung occurs in PMF = emphysematous change and:
- Black sputum
- Coal dust tattoos.
Caplan’s syndrome = Large fibrotic nodules in coal miners (pneumoconiosis) with rheumatoid arthritis