Intestinal Malrotation in Adults: A Retrospective Cross-Sectional Study Based on Computed Tomography Findings

Purpose Intestinal malrotation is an uncommon congenital anomaly that may remain clinically silent until adulthood and is increasingly detected incidentally on computed tomography (CT). Classical radiologic markers have limited diagnostic sensitivity in adults. This study evaluated the prevalence and CT characteristics of intestinal malrotation in a large adult cohort using strict CT-based diagnostic criteria. Methods A retrospective cross-sectional review of 3,478 abdominal CT scans performed between June 2023 and April 2025 was conducted. All examinations were screened for features suggestive of rotational anomalies. Suspected cases underwent a two-stage verification process by two independent radiologists. Classification as intestinal malrotation required assessment of the predominant jejunal location, cecal position, and duodenal course. Prevalence estimates and proportions were calculated with Wilson 95% confidence intervals (CI). Results Intestinal malrotation was identified in seven of 3,478 CT examinations (0.20%; 95% CI: 0.10%-0.42%). Two additional cases demonstrated atypical bowel positioning but did not fulfill the predefined primary diagnostic criteria and were excluded. The mean age of the confirmed cases was 64 ± 14 years. Gastrointestinal alarm symptoms occurred in 28.6% (two of seven) of patients, while most cases were asymptomatic. One patient presented with fatal intestinal obstruction. Conclusions Adult intestinal malrotation was uncommon and frequently detected incidentally in this CT cohort. Systematic assessment of multiple anatomical parameters may improve diagnostic confidence, as isolated anatomical deviations may mimic malrotation. These findings should be interpreted cautiously because the diagnoses were based exclusively on CT criteria, and the number of confirmed cases was small.