Gaps in the diagnosis of small bowel adenocarcinoma among patients with Crohn's disease: a tertiary care perspective.

Background: Small bowel adenocarcinoma (SBA) is a rare and serious complication of Crohn's disease (CD), with symptoms often mimicking CD-related symptoms. Therefore, preoperative diagnosis of SBA is difficult, since conventional imaging is rarely diagnostic. This study aims to evaluate the utility of imaging and endoscopic modalities in detecting SBA among patients with CD. Methods: A retrospective review of medical records from a multi-institutional tertiary care center was conducted. ICD-10 codes were used to identify patients with CD who were diagnosed with SBA between January 1, 2019, and November 24, 2024. Results: Of 92 patients identified, 36 met the inclusion criteria. Twenty-one (58.3%) were male, and 35 (97.2%) were Caucasian. The median age at SBA diagnosis was 61 years, with a median 19-year interval from initial CD diagnosis to SBA diagnosis. Thirty-one patients (86.1%) had preoperative imaging, but only 7/31 (22.6%) had findings that raised concern for malignancy. Eight (22.2%) of the patients who underwent endoscopy were diagnosed with SBA or dysplasia on endoscopic biopsy; 18 cases were discovered incidentally during surgery. Sixteen patients (44.4%) had stage III or IV cancer at diagnosis, and 18 patients (50.0%) achieved oncologic remission. Conclusions: Among patients with CD diagnosed with SBA, a large proportion of imaging and endoscopic studies failed to suggest malignancy. Given the substantial proportion of patients diagnosed at advanced stages, and the associated poor outcomes, a high index of suspicion and multimodal evaluation could improve the diagnostic yield in long-standing CD patients with new or changing symptoms.