<aside>
Inflammatory polyps, also known as pseudopolyps, are non-neoplastic projections of regenerating mucosa that arise in the setting of chronic inflammation and mucosal ulceration.
</aside>
They represent islands of residual or regenerating mucosa that protrude above the surrounding ulcerated mucosal surface — not true neoplastic polyps, hence the term pseudo.
Etiopathology
- Occur secondary to chronic mucosal injury and repetitive cycles of ulceration and healing.
- Following mucosal ulceration, the adjacent epithelium proliferates in an attempt to repair the defect.
- The regenerated mucosa overgrows unevenly, forming finger-like or polypoid projections.
- They may contain granulation tissue, fibrosis, and inflammatory cell infiltrates.
Common causes include:
- Inflammatory bowel disease (IBD) — especially ulcerative colitis (UC) and Crohn’s colitis.
- Infectious colitis (e.g., amebic, bacterial).
- Ischemic colitis.
- Post-surgical or anastomotic sites.
- Healing after mucosal injury (NSAID-induced, radiation proctitis).
Histopathology
| Component |
Description |
| Epithelium |
Non-dysplastic mucosal lining (normal or regenerative colonic epithelium). |
| Lamina propria |
Expanded and inflamed, with lymphocytes, plasma cells, and neutrophils. |
| Core |
Fibroinflammatory granulation tissue with vascular proliferation. |
| No adenomatous change |
Distinguishes from true neoplastic (adenomatous) polyps. |
- Occasionally, pseudopolyps may coalesce to form large masses — termed “inflammatory polyposis” or “giant pseudopolyposis”.
Morphologic Classification