Pseudomyxoma peritonei. A localized, benign variant of appendiceal origin.

A case of a huge, self-contained cyst of pseudomyxoma peritonei arising from the rupture of a benign cystadenoma of the appendix is reported. Curative surgical removal involved both small bowel and right colon resection. The pathologic spectrum of the appendiceal mucoceles, from mucosal hyperplasia to benign cystadenoma and malignant cystadenocarcinoma, is presented. The variants of pseudomyxoma peritonei (benign-malignant, localized-diffuse) are discussed and correlated with the appendiceal lesions. Clinicopathologic relationships and treatment options also are covered.