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 finding, often attributed to congenital anomalies, such as situs inversus or intestinal malrotation. However, it can also arise from anatomical displacement by other organs, such as redundant colonic loops. While rare, such variations may complicate the clinical and radiological diagnosis of abdominal pain and result in potentially serious consequences if not recognized. This case report highlights a left-sided appendix due to a redundant sigmoid colon incidentally discovered during the evaluation of right lower quadrant pain. A 22-year-old woman presented to the emergency department with right flank pain, which later localized to the right lower quadrant (RLQ). There was localized tenderness in the RLQ, with no systemic symptoms. A working diagnosis of acute appendicitis was considered. A noncontrast abdominal computed tomography scan revealed a 0.4 cm right lower pole nephrolithiasis without signs of appendiceal inflammation. Unexpectedly, the appendix was visualized at the mid-left lower quadrant due to displacement by a type C redundant sigmoid colon. The patient was referred to urology for further management. This report highlights the importance of recognizing anatomical variations. They may substantially alter the expected location of intra-abdominal organs and result in diagnostic confusion. Although the patient in this report did not have appendicitis, the displacement of the appendix into the left lower quadrant could have been misleading had inflammation occurred. Radiologists and clinicians should both be cognizant of atypical disease presentations, and accurate diagnosis and treatment are crucial for an optimal outcome, especially in emergency settings.