In inflammatory bowel disease, which of the following is a distinguishing histopathological feature of Crohn's disease that is absent in ulcerative colitis?

Explanation

## Histopathological Differentiation of IBD **Key Point:** Non-caseating granulomas are the hallmark histopathological feature that distinguishes Crohn's disease from ulcerative colitis. They are present in 30–50% of Crohn's disease cases but are **absent** in ulcerative colitis. ### Comparative Histopathology | Feature | Crohn's Disease | Ulcerative Colitis | Diagnostic Value | | --- | --- | --- | --- | | Non-caseating granuloma | Present (30–50%) | **Absent** | **Specific for CD** | | Transmural inflammation | Yes | No (mucosal/submucosal only) | Specific for CD | | Crypt abscess | Yes | Yes | Non-specific | | Increased IELs | Yes | Yes | Non-specific | | Loss of goblet cells | Yes | Yes | Non-specific | | Skip lesions | Yes (patchy) | No (continuous) | Specific for CD | | Fissuring ulcers | Yes | No | Specific for CD | | Crypt distortion | Mild | Marked | Favors UC | **High-Yield:** Non-caseating granulomas in Crohn's disease are composed of epithelioid histiocytes and multinucleated giant cells. They are found in the lamina propria, submucosa, or deeper layers and reflect the transmural nature of the disease. **Clinical Pearl:** Although granulomas are specific for Crohn's disease when present, their **absence does not exclude** the diagnosis. Approximately 50–70% of Crohn's disease cases lack granulomas on initial biopsy, so diagnosis relies on the full clinicopathological picture (transmural inflammation, skip lesions, fissuring ulcers). ### Why Other Features Are Non-Specific - **Crypt abscess:** Occurs in both CD and UC; represents neutrophilic infiltration of crypt epithelium - **Increased intraepithelial lymphocytes (IELs):** Present in both conditions; reflects active mucosal inflammation - **Loss of goblet cells:** Seen in both CD and UC; indicates mucosal damage and loss of secretory capacity **Mnemonic:** **GRAND** — **Gr**anulomas, Rectal sparing, **A**fter skip lesions, **N**on-transmural (UC is), **D**istribution (UC continuous). Granulomas are the **G** that makes Crohn's disease unique.