[Appendiceal mucoceles. Pathophysiology and therapeutic indications].

Appendiceal mucoceles (AM) are rare lesions of the appendix, characterized by an accumulation of mucus. Two main pathogenic mechanisms may be invoked to explain their development. Firstly, AM are secondary to an obstruction of the appendiceal lumen for a wide variety of reasons. Secondly, they may be due to tumours of the appendix, whether malignant (cystadenocarcinomas) or benign (cystadenomas), responsible for a hypersecretion of mucus. Intraperitoneal mucinous effusion (IME) develops when appendiceal perforation occurs, especially with malignant AM. We found 13 retention AM and in most a definite obstructive lesion was present. There were 3 malignant AM, all associated with a neoplastic IME. While they are frequently described in the literature, no cystadenoma was observed in these series. Clinical symptoms are often confusing, but paraclinical investigations may lead to preoperative diagnosis. Appendectomy is the treatment of retention AM and cystadenoma. Their prognosis is related to other associated diseases, namely ovarian and colorectal tumours, but is otherwise good. Cystadenocarcinomas require a right hemicolectomy with evacuation of IME but their prognosis is poor.