Figure 10: Ovarian mucinous tumor associated with pseudomyxoma peritonei. The tumor simulates a borderline ovarian mucinous tumor. A low-grade appendiceal mucinous tumor was present and both tumors were cytokeratin 7-negative and cytokeratin 20-positive, consistent with secondary involvement of the ovary by the appendiceal tumor (stains not illustrated). Submitted by Brigitte Ronnett, MD