All of the following are characteristic features of chronic inflammation EXCEPT:

Explanation

## Chronic Inflammation: Defining Features **Key Point:** Chronic inflammation is characterized by a mononuclear cell infiltrate and simultaneous tissue destruction with repair (fibrosis), NOT an acute exudative neutrophil-rich response. ### Characteristic Features of Chronic Inflammation | Feature | Details | |---------|----------| | **Cell infiltrate** | Lymphocytes, macrophages, plasma cells, fibroblasts | | **Tissue response** | Simultaneous destruction and repair (fibrosis) | | **Angiogenesis** | New blood vessel formation | | **Duration** | Weeks to months to years | | **Exudate type** | Protein-rich but NOT neutrophil-predominant | **High-Yield:** The neutrophil-rich acute exudative response is the **hallmark of acute inflammation**, NOT chronic inflammation. Chronic inflammation is defined by mononuclear cell predominance. ### Pathologic Sequence in Chronic Inflammation 1. **Mononuclear cell recruitment** (macrophages, lymphocytes) 2. **Simultaneous tissue destruction** (by macrophages and lymphocytes) 3. **Repair and fibrosis** (fibroblast proliferation, collagen deposition) 4. **Angiogenesis** (new vessel formation) **Clinical Pearl:** In chronic inflammation, the balance between destruction and repair determines the final outcome — excessive fibrosis leads to organ dysfunction (e.g., cirrhosis in chronic hepatitis, pulmonary fibrosis in chronic lung disease). **Warning:** Do not confuse the **acute phase** of chronic inflammation (which may show some neutrophils initially) with the **established chronic phase** (which is mononuclear-dominated).