48. Silicosis

Overview of the slide

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!

Close-up of a silicotic nodule

From the peripheral zone

From the central zone. No cells, just scar tissue