Prevalence of Colonic Neoplasia in Patients with a Clinical Diagnosis of Diverticulitis

Abstract

Prevalence of Colonic Neoplasia in Patients with a Clinical Diagnosis of Diverticulitis Kalyani Maganti, Kent Anderson, Joseph Leung Background: Diverticulosis of the colon is common in developed countries, and the prevalence increases with age. Diverticulitis is a major clinical complication of diverticular disease affecting 10-25% of patients. Although the American College of Gastroenterology recommends elective colonoscopy after resolution of acute inflammation to exclude neoplasia, evidence for this practice guideline is lacking. This retrospective study evaluates the prevalence of colonic neoplasia in patients with a recent clinical diagnosis of diverticulitis. Because of limited resources, we determine if elective colonoscopy impacts on the outcome of this specific group of patients. Methods: We identified all patients with a diagnosis of diverticulitis by ICD-9 codes between 1996 and 2005 at our institution and those who had undergone colonoscopy within one year of the diagnosis. Patient demographics, indications, colonoscopy findings and location of significant pathology were reviewed. Primary outcomes included finding of polyps and advanced neoplasia defined as tubular adenoma O/Z 1 cm, villous histology, high grade dysplasia or cancer. Statistical analysis was performed using exact binomial 95% two-sided confidence interval. Results: A total of 16964 colonoscopies were performed during this period. 2305 patients with a ICD-9 diagnosis of diverticulitis were identified. Of these, 239 patients underwent colonoscopy within 1 year of the diagnosis. 25 patients had a poor preparation, 22 of whom had adequate examinations. Of the 236 patients, 139 were female, 97 male. Mean age was 59 years. 9 patients (3.8%) had family history of colon cancer, and 17 (7.2%) patients had history of prior colonic polyps. Significant findings on colonoscopy were 74 (31.3%) patients with polyps, 38 (16.1%) had tubular adenomas, 5 (2.1%) O10 mm. There was no cancer and no villous histology or high grade dysplasia noted on any polyps in this series. 17 patients had hyperplastic polyps. Based on analysis of our data, the probability of cancer being found at colonoscopy in this group of patients with a diagnosis of diverticulitis is !1%. Conclusions: Our data indicated that the coexistence of colonic neoplasia with diverticulitis is not significant compared to the general population. Considering the limited resources, a clinical diagnosis of uncomplicated diverticulitis in and by itself does not warrant a colonoscopy to rule out neoplasia. However, the standard screening expectations still apply.