Pseudomyxoma retroperitonei associated with appendiceal cystadenoma.

Pseudomyxoma peritonei is a rare condition in which the peritoneal cavity is full of thick gelatinous deposits, thought to represent a tumor of varying degrees of malignancy. Most cases originate from ruptured ovarian cysts or appendiceal mucoceles, and involve the intraperitoneal cavity alone. There have only been two previously reported cases of extraperitoneal pseudomyxoma in the English literature. This report describes a case of pseudomyxoma retroperitonei arising from an appendiceal mucinous cystadenoma. The pathologic elements of the disease process, as well as treatment options, are discussed.