S2402 A Case Report of Early Eosinophilic and Ulcerative Colitis

Abstract

Introduction: Eosinophilic colitis (EC) is a rare inflammatory gastrointestinal disorder with a poorly understood pathophysiology. Recent studies suggest that eosinophil-driven breakdown of colonic wall structure may be contributing to both EC and early stages of inflammatory bowel disease (IBD). We report a case of a young woman with biopsy findings suggestive of both EC and ulcerative colitis (UC) in an early disease state. Case description/methods: An 18 year old female with a history of irritable bowel syndrome (IBS) for 2 years, obesity (BMI 31), depression, anxiety, migraines and ovarian cysts presents for outpatient colonoscopy for suspected ulcerative colitis after 3 months of diarrhea, vomiting, diffuse abdominal pain, chills and body aches. A CT abdomen showed a 12mm left ovarian cyst and no other discernible pathology. Her medications include bupropion, escitalopram, hydroxyzine, Depo-Provera, dicyclomine, and mesalamine rectal enema. She denies toxic habits and her vital signs were unremarkable. Her CMP, CBC and coagulation panels were also unremarkable, and COVID testing was negative. Her colonoscopy showed diffuse mild inflammation extending from the rectum to the descending colon suggestive of left-sided ulcerative colitis. Biopsies were taken from the right colon, left colon and terminal ileum. Pathology report showed mild active colitis with moderate eosinophilia in the right colon with at least 50 eosinophils per high power field (HPF), with similar findings in the left colon. The eosinophilia extended into the lamina propria with focal epithelial invasion of eosinophils, but no overt distortion of crypts or other signs of chronic colitis were noted. The terminal ileum showed no diagnostic pathology. Overall, the findings suggest a combination of early ulcerative colitis with eosinophilic colitis. Discussion: First described in the mid-19th century, eosinophils are continuously active in mucus and antibody secretion and should populate colonic mucosa in counts no higher than 50 per high power field. In contrast to EC, UC is characterized by mucosal infiltration by neutrophils helped in part by eosinophilic secretion of chemokines. Although our patient demonstrates left-sided colitis, histology did not show characteristic crypt abscesses nor neutrophilic invasion, but rather an eosinophilic predominance with a relatively mild phenotype. In light of current pathophysiologic literature, this may represent an early stage of UC development, or a mixed EC/UC phenotype rarely observed otherwise. (Figure Presented).