Incidental leftward displacement of the appendix due to redundant sigmoid colon: A case report of anatomical variation

Abstract

A left-sided appendix is an uncommon clinical entity, often attributed to congenital anomalies such as situs inversus or intestinal malrotation; however, it can also result from anatomical displacement by other organs. We report a case of a 22-year-old woman presenting to the emergency department with right lower quadrant pain which was initially suspected as appendicitis. A non-contrast computed tomography (CT) scan identified a right kidney stone as the source of pain, alongside an incidentally discovered, non-inflamed appendix displaced entirely into the mid-left lower quadrant. A radiological review was done to exclude congenital causes of the presentation, such as non-rotation. The normal orientation of the superior mesenteric vessels and the duodenojejunal junction ruled out malrotation, confirming that the cross-midline appendiceal shift was caused by a Group IV redundant sigmoid colon. This report emphasizes the importance of thorough evaluation and imaging awareness. Careful assessment helps prevent falling into a radiologic pitfall where a redundant colon mimics the anatomical presentation of congenital malrotation, thereby avoiding diagnostic confusion and inappropriate management.