S1718 An Unusual Presentation of a Rare Disease: Eosinophilic Colitis Presenting as Cecal Mass

Abstract

INTRODUCTION: Eosinophilic colitis (EC) is a rare condition which most commonly presents with abdominal pain and diarrhea. We present a unique case of EC which was associated with an ulcerated cecal mass and sigmoid thickening. CASE DESCRIPTION/METHODS: An 89 year-old-male with a history of asthma, partial gastrectomy, and vagotomy presented with fever, abdominal pain, and diarrhea for 6 weeks. A colonoscopy performed 3 years prior to presentation was unremarkable. Physical examination was unremarkable. Lab work revealed leukocytosis with eosinophilia (800 /μL). Computed Tomography (CT) of the abdomen showed splenic flexure colitis. He was empirically treated with antibiotics and intravenous hydration with symptomatic improvement. Stool analysis for infection was negative. Follow-up CT of the abdomen demonstrated resolution of colitis. Persistence of diarrhea several months later prompted a colonoscopy that revealed a small, non-obstructing, friable, infiltrative, ulcerated mass in the caecum and a similar small satellite lesion. There were signs of patchy colitis, and an edematous thickened fold in the sigmoid colon. Histopathological analysis of biopsy samples revealed Intense eosinophilic infiltration involving the mucosa, muscularis mucosa, and submucosa, with variably sized clear spaces, suggestive of pneumatosis intestinale. Repeat lab work, including complete blood count, antinuclear antibodies (ANA), anti-neutrophil cytoplasmic antibodies (ANCA), immunoglobulin E, and stool analysis was unremarkable; notably, there was no eosinophilia. The diagnosis of primary EC was made by elimination. First-line treatment with an elimination diet was instituted. DISCUSSION: EC is characterized by chronic diarrhea and/or abdominal pain with eosinophilic infiltrate in the colonic wall. Although EC usually presents in a bimodal distribution (neonates, young adults), our patient was considerably older. The diagnosis is largely one of exclusion due to a lack of clear diagnostic criteria. Unlike eosinophilic esophagitis, there is no specific threshold of eosinophilic density. Secondary causes of eosinophil infiltration such as parasitic infection and malignancy should be ruled out. Treatment consists of elimination diet, tapering course of corticosteroids, and immunomodulatory agents. Due to a lack of specific diagnostic criteria, it is imperative to have a high clinical suspicion and avoid disregarding differentials based on age. Of note, EC presenting as a mass has only been described once previously to our knowledge.