3. Coal Workers’ Pneumoconiosis
• Coal workers’ pneumoconiosis is lung disease caused by inhalation
of coal particles and other admixed forms of dust
Asymptomatic anthracosis
Simple coal workers
pneumoconiosis
Complicated Coal workers
pneumoconiosis OR
Progressive massive
fibrosis
Coal workers may also develop emphysema and
chronic bronchitis independent of smoking.
4. Anthracosis
(anthrac- meaning coal, carbon + -osis meaning condition)
“the asymptomatic, milder type of pneumoconiosis as
caused by the accumulation of carbon in the lungs due
to repeated exposure to air pollution or inhalation of
smoke or coal dust particles”.
5. Pathogenesis:
• Inhaled carbon pigment is engulfed by alveolar or interstitial
macrophages,
• then accumulate in the connective tissue along the lymphatics,
• including the pleural lymphatics, or in organized lymphoid tissue
along the bronchi or in the lung hilus.
6.
7.
8. SIMPLE COAL-WORKERS’ PNEUMOCONIOSIS.
• Grossly, the lung parenchyma shows small, black focal lesions, measuring less than 5 mm
in diameter and evenly distributed throughout the lung but have a tendency to be more
numerous in the upper lobes. These are termed coal macules, and if palpable are called
nodules. The air spaces around coal macules are dilated with little destruction of alveolar
walls. Though some workers have called it centrilobular emphysema of coalminers,
others prefer not to consider it emphysema because there is no significant destruction of
alveolar walls. Similar blackish pigmentations are found on the pleural surface and in the
regional lymph nodes
• Histologically, the following features are seen:
1. Coal macules are composed of aggregates of dust laden macrophages. These are
present in the alveoli and in the bronchiolar and alveolar walls
2. There is some increase in the network of reticulin and collagen in the coal macules.
3. Respiratory bronchioles and alveoli surrounding the macules are distended without
significant destruction of the alveolar walls.
9. PROGRESSIVE MASSIVE FIBROSIS.
• Grossly, besides the coal macules and nodules of simple pneumoconiosis, there are
larger, hard, black scattered areas measuring more than 2 cm in diameter and sometimes
massive. They are usually bilateral and located more often in the upper parts of the lungs
posteriorly. Sometimes, these masses break down centrally due to ischaemic necrosis or
due to tuberculosis forming cavities filled with black semifluid resembling India ink. The
pleura and the regional lymph nodes are also blackened and fibrotic.
• Histologically, the following features are present:
1. The fibrous lesions are composed almost entirely of dense collagen and carbon
pigment.
2. The wall of respiratory bronchioles and pulmonary vessels included in the massive
scars are thickened and their lumina obliterated.
3. There is scanty inflammatory infiltrate of lymphocytes and plasma cells around the
areas of massive scars.
4. The alveoli surrounding the scars are markedly dilated.
