Unmasking the false cecal polyp: a case of inverted appendix—a case report and review of the literature

An inverted appendix is a rare incidental finding on colonoscopy, often misinterpreted as a neoplastic lesion. A 74-year-old woman underwent routine screening colonoscopy that revealed a cecal polypoid lesion near the appendiceal orifice. Initial biopsies showed nonspecific inflammation, and a subsequent contrast-enhanced computed tomography (CT) scan reported only sigmoid diverticulosis. During a repeat in-hospital colonoscopy, the lesion was re-evaluated and identified as an inverted appendix, preventing unnecessary resection. Retrospective review of the CT images confirmed the diagnosis. Appendiceal inversion may result from surgical manipulation, intussusception, or rarely congenital causes, and is characterized endoscopically by origin at the appendiceal orifice, normal mucosa, and distinctive imaging features. Rarely, it may be associated with mucinous, neuroendocrine, or endometriotic lesions. Awareness of this entity is vital, as biopsy or removal of benign-appearing lesions is not indicated and may result in bleeding or perforation. Careful endoscopic assessment and imaging review are essential to avoid unnecessary resection.