S6023 An Unexpected Source of GI Bleeding: Enteric Muco-Submucosal Elongated Polyp in the Proximal Jejunum With Literature Review

Introduction: Enteric muco-submucosal elongated polyps (EMSEPs) represent a rare poorly characterized entity within the spectrum of gastrointestinal polypoid lesions. While most documented cases involve the colon, their occurrence in the small intestine remains uncommon. We present a case of an 85-year-old man with iron deficiency anemia (IDA) who was noted to have a large jejunal EMSEP with stigmata of recent hemorrhage (SRH). Case Description/Methods: Eighty-five-year-old man with no past medical history on prophylactic Aspirin presented for evaluation of IDA. Imaging revealed colonic diverticula, small hiatal hernia, and proximal small bowel fat densities. Esophagogastroduodenoscopy revealed mild gastritis, negative for H. pylori and celiac disease, and colonoscopy showed sigmoid diverticulosis, hemorrhoids, and a 3 mm cecal tubular adenoma. For further evaluation, a small bowel enteroscopy was performed, which showed a 10 mm subepithelial nodule in the third portion of the duodenum consistent with lipoma and a large lesion (5 cm long) with SRH in the proximal jejunum. Biopsy revealed preserved villous architecture with focal acute inflammation. The lesion was clinically diagnosed as EMSEP. Patient chose not to proceed with endoscopic resection as his hemoglobin was stable on periodic iron infusions. Discussion: EMSEPs are often asymptomatic and may present incidentally during endoscopic evaluation. Their potential to cause symptoms including bleeding, anemia, or bowel obstruction, as evidenced by our patient’s presentation of anemia and the identification of a large, elongated lesion in the jejunum, underscores EMSEPs’ clinical significance. This is a unique presentation, as most cases of EMSEPs are found in the colon, and there is limited literature describing their occurrences in the small bowel. Furthermore, the lesion in our case had SRH-a salient finding that is not typically described in the literature. These polyps are characterized by their elongated shape and a histological composition involving mucosal hyperplasia, submucosal fibrosis, elongated glands, fibrotic stroma, and mild inflammatory changes. However, as noted in our case, histology can sometimes be nondiagnostic. The absence of definitive histological findings is in line with other reports that describe cases of EMSEPs with varying degrees of diagnostic clarity. This case highlights the need for thorough small bowel evaluation in unexplained anemia and ongoing research to improve EMSEP diagnosis and management.