Clinical Features and Management of Small Bowel Masses Detected During Device-Assisted Enteroscopy: A Multi-Center Experience.

Background: Small bowel mass lesions (SBMLs) are rare, span a range of different histologies and phenotypes, and our understanding of them is limited. Some lesions occur in patients with recognized polyposis syndromes and others arise sporadically. The current literature regarding SBMLs is limited to small retrospective studies, case reports, and small case series. This large multi-center study aims to understand the various clinical presentations, histologies and management options for SBMLs.

Methods: After obtaining Institutional Review Board (IRB) approval, electronic records were used to identify all device-assisted enteroscopy (DAE) performed for luminal small bowel evaluation in adult patients at three US referral centers (Duke, LSU and UMass) from January 1, 2014, to October 1, 2020. We identified all patients within this cohort in whom a SBML was detected. Using a focused electronic medical record chart review, we collected patient, procedure, and lesion-related data and used descriptive statistics to explore relationships between these data and outcomes.

Results: A total of 218 patients (49 at Duke, 148 at LSU, and 21 at UMass) in this cohort had at least one SBML found on DAE. The most common presenting symptoms were iron-deficiency anemia/bleeding (73.3%) and abnormal imaging (33.6%). Thirty-five percent of patients had symptoms for more than a year prior to their diagnosis. Most patients (71.6%) underwent video capsule endoscopy (VCE) prior to DAE and 84% of these exams showed the lesion. The lesion was seen less frequently (48.9%) on computed tomography (CT) scan performed prior to DAE. The majority of lesions were found on antegrade (56%) or retrograde (29.8%) double-balloon enteroscopy (DBE). The most common lesion phenotypes were submucosal (41.3%) and pedunculated (33%) with a much smaller number being sessile (14.7%) or obstructing/invasive (11%). They were found equally as commonly in the jejunum (46.3%) and ileum (49.5%). Most lesions were 10 - 20 mm in size (47%) but 22.1% were larger than 20 mm. The most common histologies were neuroendocrine tumors (NETs, 20.6%) and hamartomas (20.6%). Primary adenocarcinoma of the small bowel was rare, constituting only 5% of lesions. The majority of polyps (78.4%) were sporadic, compared to 21.7% associated with a polyposis or hereditary cancer syndrome, most commonly Peutz-Jeghers syndrome (18.3%). After DAE, 37.6% were advised to undergo surgical resection and 48% were advised to undergo endoscopic surveillance or no further management because of benign histology or successful endoscopic resection.

Conclusions: In this multi-center retrospective study we found that SBMLs are more likely to be sporadic than syndromic, medium in size and either pedunculated or submucosal. NETs and hamartomas predominated and symptoms, most commonly anemia, can be present for more than a year prior to diagnosis. Close to one half of lesions required either no further intervention or only endoscopic surveillance.