Pseudomyxoma peritonei usually originates from the appendix: a review of the evidence.

Pseudomyxoma peritonei (PMP) is a rare condition, said to be more common in females during the fourth or fifth decade of life with an incidence believed to be in the region of one per million per year. Although PMP has been reported as originating from many intra-abdominal organs, in the majority of cases an ovarian or appendix cystadenoma or cystadenocarcinoma has been implicated as the primary site. Our experience suggests that most cases arise from the appendix. We have reviewed the clinical and scientific evidence. In the four largest reported series of 393 patients, 181 (46%) were males. Immunohistochemistry techniques in women with both appendical and ovarian tumours favour an appendiceal primary in most cases. The distinction between "benign" adenomucinosis and mucinous adenocarcinoma is important in both treatment and prognosis. Experience suggests that there may well be a spectrum of disease and possibly an "adenoma carcinoma sequence".