[Retrocecal mucus-secreting tumors of the appendix (mucoceles). Apropos of 3 radiologically diagnosed cases].

The term of appendiceal mucocele has been applied to a group of lesions distending the lumen of the appendix; filled with mucus. About 15% of these lesions are malignant tumors (cystadenocarcinomas). All these lesions may lead to pseudomyxoma peritonei, but only the peritoneal involvement due to a malignant tumor (adenocarcinoma) has multiple recurrences and poor prognosis. Benign lesions are cured by appendicectomy, even if a peritoneal "gelatinous" effusion is present. These lesions can usually be early diagnosed by US and CT features if the mucocele extends behind the cecum in the retroperitoneal space, especially if the wall is calcified. A colic examination (with barium enema or colonoscopy) must be taken event if the diagnosis is made by US or CT means, because of the significant association of mucocele with other colonic tumors.