A patient's abdomen becomes distended with loculated masses of semi-translucent mucinous material produced by a mucinous cystadenoma. Which of the following are the most likely sites for the primary tumor?

This rare, but dramatic, condition is called pseudomyxoma peritonei, and is produced when a malignant or benign (spread by rupture into the peritoneal cavity rather than true metastasis) mucus producing tumor (mucinous cystadenoma or mucinous cystadenocarcinoma) produces gel-like mucus that fills the peritoneal cavity. The usual sites of origin of these tumors are ovary and appendix. The condition, even when benign, is difficult to treat because the mucus producing cells are spread all over the peritoneal lining, and cannot be effectively removed. Home parenteral nutrition may be necessary as the gut (paicularly peristalsis) just does not function well in a sea of Jell-O that slowly becomes replaced with fibrous tissue bands. Ref: Jaffe B.M., Berger D.H. (2010). Chapter 30. The Appendix. In F.C. Brunicardi, D.K. Andersen, T.R. Billiar, D.L. Dunn, J.G. Hunter, J.B. Matthews, R.E. Pollock (Eds), Schwaz's Principles of Surgery, 9e.