Three-dimensional computed tomography rendering of pedunculated colon polyp: new “clapper-bell” sign pedunculated polyp at 3D computed tomography

The incidental detection of a tubulovillous adenoma at a contrast-enhanced computed tomography (CECT) with nondedicated protocol, performed in emergency conditions, is an uncommon finding. We report a case of a woman presenting with a subocclusive episode. A CECT scan was performed, and a pedunculated polyp could be appreciated at 3D-reconstruction images. A particular depiction of pedunculus of the polypoid lesion, resemble a clapper-bell, could help to define the vegetating lesion at the volume-rendering reconstruction images. This case emphasizes the fundamental role of postprocessing in the clinical practice to improve the diagnostic accuracy of abdominal CT scan. In addition, a potential new radiologic sign, the “clapper-bell sign”, is proposed, as literature about the appearance of a polyp at CECT, performed without a dedicated protocol for colonoscopy, is poor.