48. Silicosis
Staining: HE
Organ: Lung
Description:
The lung parenchyme is normal, however some large nodules can be seen. These nodules have two zones, the peripheral zone and central zone. Anthracosis is also present. The peripheral zone contains macrophages and fibroblasts. The central zone contains scar tissue and no cells.
Diagnosis: Silicosis
Causes:
- Silica dust inhalation
Theory:
The central zone contains no cells, so it can be mistaken for necrosis. Compare these silicotic nodules to the necrotic granulomas in miliary tuberculosis and don’t mix them!