The histopathology of Usual Interstitial Pneumonia (UIP) is characterized by a specific pattern of lung tissue changes when viewed under a microscope.
Key Histopathological Features of UIP
| Feature | Description |
|---|---|
| Patchy Fibrosis | The fibrosis, or scarring, is not uniform; it appears in patches of varying intensity throughout the lung tissue. |
| Dense Fibrosis | The affected areas show significant dense fibrosis, indicating a substantial buildup of scar tissue. |
| Lung Architecture Remodeling | The fibrosis causes a remodeling of the normal lung architecture, disrupting its structure and organization. |
| Honeycomb Change | In severe cases, fibrosis results in the formation of honeycomb-like spaces (cystic spaces surrounded by dense fibrosis). This is a characteristic but not required feature of UIP, according to the reference, and represents severe tissue destruction. |
| Alternating Areas | The areas of dense fibrosis and honeycomb change alternate with areas of lung tissue that are relatively less affected. This contributes to the patchy nature of the disease. The areas of less affected parenchyma can also be the focus of investigation to confirm the patchy distribution of changes. |
As the reference mentions, the key to identifying UIP is recognizing the low-magnification appearance of the patchy dense fibrosis, remodeling lung architecture, and the frequent (but not always present) honeycomb changes, with these areas interspersing with areas of less damaged lung tissue. These findings help differentiate UIP from other lung diseases.
