The appendix may rarely become distended with sterile mucus. The causes may include simple obstruction by an appendicolith, hyperplasia of the appendix mucosa with overproduction of mucus, a mucinous cystadenocarcinoma of the appendix, or a mucinous adenocarcinoma. A mucocele is found in approximately 0.1% of appendectomies. The patient usually presents with vague abdominal pain, however, approximately 25% are asymptomatic and the mucocele is discovered incidentally at laparoscopy. They appear as oblong, low attenuation masses extending from the cecum. They may occasionally have rim calcification. If a mucinous cystadenocarcinoma ruptures into the abdomen then the patient will develop persistent gelatinous ascites which is extremely difficult to manage. This malignant, gelatinous ascities can displace and/or scallop organs. Chronic cases will develop septations which will often calcify.