Coiled-spring sign of the cecum in acute appendicitis.

A concentric ring appearance of the cecal mucosa on a barium enema is a distinctive but nonspecific radiographic finding that has been termed the vortical, whirlwind, or coiled-spring sign. It can be caused by inversion of a postappendectomy stump and transient intussusception of the intact appendix in asymptomatic patients. The sign has also been reported with mucoceles, carcinoma, and endometriosis of the appendix, but there has been little mention of it in connection with acute appendicitis. The records of 18 patients with a coiled-spring sign and nonfilling of the appendix were reviewed. Acute appendicitis was proven in 14 of 18. In five of these 14, this sign was the only finding accompanying nonfilling of the appendix. On review of 53 cases of pathologically proven acute appendicitis studied by preoperative barium enema, 14 had a coiled-spring sign. The coiled-spring sign is nonspecific but can be produced by acute appendicitis, where it may be the only positive sign accompanying nonfilling of the appendix.