Retrospective Study
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World J Gastroenterol. Sep 28, 2014; 20(36): 13139-13145
Published online Sep 28, 2014. doi: 10.3748/wjg.v20.i36.13139
Identification of pathologic features associated with “ulcerative colitis-like” Crohn’s disease
Samuel D James, Paul E Wise, Tania Zuluaga-Toro, David A Schwartz, M Kay Washington, Chanjuan Shi
Samuel D James, M Kay Washington, Chanjuan Shi, Departments of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, United States
Paul E Wise, Section of Colon and Rectal Surgery, Washington University in St. Louis, Gainesville, MO 63130, United States
Tania Zuluaga-Toro, Department of Pathology, University of Florida, Gainesville, FL 32611, United States
David A Schwartz, Departments of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, Nashville, TN 37232, United States
Author contributions: James SD and Shi C performed the majority of the microscopic evaluations and wrote the manuscript; Wise PE and Schwartz DA provided clinical and surgical management of patients involved in the study and were also involved in editing the manuscript; Shi C, Washington MK and Zuluaga-Toro T designed the study and were also involved in editing the manuscript.
Correspondence to: Chanjuan Shi, MD, PhD, Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, 1161 21st Avenue South, C-3321 MCN, Nashville, TN 37232, United States. chanjuan.shi@vanderbilt.edu
Telephone: +1-615-9368342 Fax: +1-615-3437023
Received: January 4, 2014
Revised: March 29, 2014
Accepted: April 30, 2014
Published online: September 28, 2014
Processing time: 270 Days and 15.8 Hours
Abstract

AIM: To identify pathologic features associated with this “ulcerative colitis (UC)-like” subgroup of Crohn’s disease (CD).

METHODS: Seventeen subjects diagnosed as having UC who underwent proctocolectomy (RPC) from 2003-2007 and subsequently developed CD of the ileal pouch were identified. UC was diagnosed based on pre-operative clinical, endoscopic, and pathologic studies. Eighteen patients who underwent RPC for UC within the same time period without subsequently developing CD were randomly selected and used as controls. Pathology reports and histological slides were reviewed for a wide range of gross and microscopic pathological features, as well as extent of disease. The demographics, gross description and histopathology of the resection specimens were reviewed and compared between the two groups.

RESULTS: Patients with “UC-like” CD were on average 13 years younger than those with “true” UC (P < 0.01). More severe disease in the proximal involved region and active ileitis with/without architectural distortion were observed in 6 of 17 (35%) and 7 of 17 (41%) “UC-like” CD cases, respectively, but in none of the “true” UC cases (P < 0.05). Active appendicitis occurred in 8 of 16 (50%) “UC-like” CD cases but in only two (11%) “true” UC cases (P < 0.05). Conspicuous lamina propria neutrophils were more specific for “UC-like” CD (76% vs 22%, P < 0.05). In addition, prominent lymphoid aggregates tended to be more common in “UC-like” CD (P = 0.07). The “true” UC group contained a greater number of cases with severe activity (78% vs 47%). Therefore, the features more commonly seen in “UC-like” CD were not due to a more severe disease process. Crohn’s granulomas and transmural inflammation in non-ulcerated areas were absent in both groups.

CONCLUSION: More severe disease in the proximal involved region, terminal ileum involvement, active appendicitis, and prominent lamina propria neutrophils may be morphological factors associated with “UC-like” CD.

Keywords: Ulcerative colitis-like Crohn’s disease; Ulcerative colitis; Crohn’s colitis; Inflammatory bowel disease

Core tip: Despite well-established clinical and pathological criteria, a fraction of Crohn’s disease (CD) cases are diagnosed as ulcerative colitis (UC). Given the significant difference in standard surgical management for UC and Crohn’s colitis, it is critical to identify as many factors as possible which may help distinguish the two entities. In this study we have identified several pathologic features which may assist in identifying a subgroup of inflammatory bowel disease cases known as “UC-like” CD. More severe disease in the proximal involved region, terminal ileum involvement, active appendicitis, and prominent lamina propria neutrophils may be morphological factors associated with “UC-like” CD.