The Peri-Appendiceal Red Patch

Abstract

Purpose: Population-based studies and case series suggest a pathogenetic role of the appendix in patients with ulcerative colitis (UC), but the clinical characteristics and behavior of patients with less than pancolitis and co-existent inflammation of the cecum or the so-called “peri-appendiceal red patch” (PARP) are not fully understood. Aim We used a tertiary care center database of UC patients to review the clinical characteristics of those with PARP. Methods: Using the University of Chicago IBD Endoscopy Database (1994-present), patients with a clinical diagnosis of UC were selected. Those with less than pancolitis and in whom a “cecal red patch” or “periappendiceal red patch” was described were identified. Clinical and histologic characteristics of these patients were then reviewed using electronic medical records. Results: 688 UC patients who had complete colonoscopy were identified, 367 of whom did not have pancolitis (51% male). 29 (7.9%) of these patients had endoscopically described PARP (17% proctitis, 6% proctosig, 56% left-sided, 19% extensive, 1% unknown), 20 of whom were further confirmed by biopsy of the area. None of the 29 patients had a prior appendectomy, 8 (28%) were ex-smokers, and 26 (79%) were male. In 16 of 24 (67%) exams in which biopsies were obtained, the histologic activity in the PARP paralleled the activity documented in the distal colon. 2 patients required colectomy for fulminant colitis at the time of referral. Of the remaining 27 patients, 23 had median 7 y f/u (range 1–16y), and these referred patients had a total duration of disease of 12 y (median, range 1–22 y). 18/23 patients had colonoscopies during their f/u which identified progression to greater extent of disease in 5 (28%) at 13 y (median, range 9–21 y). One progressing patient developed dysplasia during f/u after 18 years of disease and underwent colectomy. Conclusions: In our tertiary care center, we have also observed the association of peri-appendiceal inflammation in a subset of patients with the otherwise clinical features of UC. The lack of appendectomy, male preponderance, and parallel activity to the distal colon are important observations that warrant further investigation into the potential relationship of peri-appendiceal red patch and UC.