Appendicular Histology and Its Clinical Significance in Patients with Ulcerative Colitis

Background and aims: The appendix may be involved in ulcerative colitis (UC) to variable extent. Clinical significance of appendicular involvement is not clear and it has long been considered an innocent bystander. This study prospectively investigated appendiceal histology and its clinical significance in patients with UC. Materials and methods: Colonoscopy was performed in 60 patients and biopsies were taken from appendiceal orifice, cecum, and colon. Appendiceal histology was classified as active if there was presence of neutrophils with crypt distortion. Inactive inflammation was defined as positive for crypt distortion and negative for neutrophils. Otherwise the histology was reported as normal or nonspecific changes. The patients were followed for a minimum period of 6 months. Results: In patients evaluated endoscopically, 63% patients had histological involvement of the appendiceal orifice. Pancolitis was seen more commonly in patients with appendicular orifice inflammation than in patients with normal appendicular histology (44.7 vs 9%, p = 0.001). Most patients with appendiceal orifice inflammation had involvement of the cecum. Skip lesion of the appendix without cecum involvement was seen in 37% of the patients. The patients with appendiceal orifice inflammation had a significantly higher grade of endoscopic colitis compared to patients with normal histology (p = 0.006). Relapse rate was higher in patients with appendiceal orifice inflammation than in patients with normal appendiceal histology (18.4 vs 9%), although the difference was insignificant (p = 0.329). Conclusion: Appendicular involvement in ulcerative colitis is not uncommon. Its involvement may predict the course, extent, and severity of colitis.