Synchronous mucinous tumors of the ovary and the appendix associated with pseudomyxoma peritonei: CT findings

Background: To present the computed tomographic (CT) findings of synchronous mucinous tumors of the ovary and the appendix associated with pseudomyxoma peritonei (PMP). Methods: Imaging studies, mainly abdominal CT scans, of three women aged 49-75 years were reviewed. Attention was directed to the ovarian masses, peritoneal seeding, and the presence of an appendiceal mucocele. Results: The ovarian tumors and the appendiceal mucocele were clearly demonstrated in two cases, and they were part of the extensive PMP in the third patient. Ascites was found in all cases, with internal septation in one. Associated scalloping of the liver margins and hypodense peritoneal implants, with extensive bowel involvement, were seen in another one. Pathologically, there was one case of right ovarian mucinous cystadenoma and villous adenoma of the appendix, one case of right ovarian and appendiceal mucinous cystadenocarcinoma, and one case of bilateral metastatic ovarian implants of appendiceal mucinous cystadenocarcinoma. PMP was found in all. In the case with benign tumors of the ovary and the appendix, the PMP was classified as a benign mucinous spillage. This patient returned 33 months after surgery with PMP, in which epithelial cells were found. Conclusions: Radiologists should be familiar with the clinical occurrence of synchronous mucinous tumors of the ovary and the appendix associated with PMP and with the typical CT findings of the latter two entities. Alternatively, when the imaging findings suggest ovarian cystic tumor with PMP, the radiologist should be alerted to the probability of a clinically unsuspected appendiceal mucocele and should search for it.