Pneumoconioses is a group of diseases characterized
by a diffuse fibrotic reaction in the lungs induced
by inhalation of organic or inorganic particulate matter
and chemical fumes and vapors. The pathogenesis of the fibrosis is
through the release of fibrogenic chemical mediators. (Refer to Table 15-8 in your
Although the end-point is fibrosis, the pattern and location varies with the type.
- Coal Workers' Pneumoconiosis:
The pathology ranges from anthracosis (carbon deposited in lung macrophages and
lymphatics) to progressive massive fibrosis. The fibrosis occurs primarily in the upper zones of the lungs. (Refer to Figure 15-25 in your
- Silicosis: Silica is ingested by macrophages. The activated
macrophages release powerful chemical mediators like interleukin-1 and tissue necrosis
factor which cause fibrosis. nodular fibrosis and larger, dense scars occur primarily in
the upper zones of the lung. Silica is present in the nodules. (Refer to Figures 15-29 and
15-30 in your textbook).
- The primary pathology in the lung is diffuse interstitial fibrosis which early on
predominates in the lower zones of the lungs. The
asbestos body is a unique feature of this type of fibrosis. (Refer to Figure 15-31 in
- Pleural plaques (circumscribed areas of fibrosis) are the most common
manifestation of asbestosis.
- High incidence of mesothelioma and bronchogenic carcinoma.
- Berylliosis: Beryllium induces cell-mediated immunity resulting
in non-caseating granulomas scattered throughout the lungs and hilar lymph nodes. The
granulomas "burn out," becoming fibrotic and forming fine nodular densities
throughout the parenchyma.