David Madwed ; R. Mindelzun ; R.B. Jeffrey, Jr.

Mucocele of the appendix, a cystic mass resulting from a dilated appendiceal lumen caused by abnormal accumulation of mucus, is a rare entity that often is not considered when problems of the right lower quadrant are assessed. Preoperative recognition of mucocele of the appendix is important because of the possibility of rupture at surgery with development of pseudomyxoma peritonei and to predict malignant transformation. The appearances of mucoceles of the appendix on sonography, CT, and barium studies are illustrated. Mucocele of the appendix, a descriptive term that implies a dilated appendiceal lumen caused by abnormal accumulation of mucus, is a rare clinical entity; the reported prevalence in appendectomy specimens at surgery is 0.2-0.3% [1]. A correct preoperative diagnosis is rarely made on the basis of clinical examination or findings on conventional radiographs. Accurate diagnosis is essential in order to prevent rupture at surgery with development of pseudomyxoma peritonel and to predict malignant transformation. The advent of advanced imaging techniques, particularly CT and sonography, has been invaluable in the diagnosis of mucocele of the appendix. This report details the wide spectrum of findings of mucocele of the appendix on sonography, CT, and barium studies.