Pneumoconiosis

Question 1

What are the different types of pneumoconiosis?

Answer 1

Coal workers' pneumoconiosis.
Bauxite fibrosis.
Berylliosis.
Silicosis.
Siderosis.
Asbestosis.

Question 2

What is coal workers’ pneumoconiosis caused by?

Answer 2

Inhaling coal dust.
The dust particles accumulate in the lung parenchyma and are engulfed by macrophages. These macrophages then die, releasing enzymes resulting in tissue fibrosis.

Question 3

What is bauxite fibrosis caused by?

Answer 3

Inhaling bauxite fumes (a.k.a. Shaver’s disease).

Question 4

What is berylliosis caused by?

Answer 4

Inhaling beryllium.

Question 5

What does berylliosis cause?

Answer 5

Granuloma formation, made up of giant cells, macrophages and epithelioid cells.

Question 6

List other granulomatous conditions.

Answer 6

Tuberculosis
Leprosy
Cat-scratch disease
Sarcoidosis

Question 7

What is silicosis?

Answer 7

Caused by inhaling silica particles, which cannot be removed by respiratory defences.
Macrophages engulf the silica particles releasing tumour necrosis factor (TNF) and cytokines that induce fibroblasts, resulting in fibrosis and collagen deposition.
Associated with increased TB infection.
Eggshell calcification of hilarity lymph nodes is apparent on CXR, along with nodular lesions in the upper lobes.

Question 8

What is siderosis?

Answer 8

Caused by inhaling iron particles.

Benign with no apparent respiratory symptoms or altered lung function.

Question 9

What is asbestosis?

Answer 9

Caused by inhaling asbestos fibres. The fusiform rods are found inside macrophages.
Associated with malignant mesothelioma.
Pleural plaques are apparent on CXR.
White asbestos has the lowest fibrogenicity, whereas blue asbestos has the highest.