Pseudomyxoma peritonei associated with ovarian mucinous tumors. Cytologic appearance in five cases.

The cytologic findings in five cases of pseudomyxoma peritonei associated with ovarian mucinous tumors are reported. The evidence suggests that if mucinous or gelatinous ascitic fluid is received in the laboratory and is shown to contain a dual cell population of round cells of mesothelial origin and spindle-shaped cells of fibroblastic origin together with lakes of fibrillar mucin, a cytologic diagnosis of pseudomyxoma peritonei can be made with confidence. It will usually indicate mucinous neoplasia of the appendix or ovary. In the case of ovarian neoplasia, the tumor is most likely to be a low-malignant-potential mucinous tumor. The patient's prognosis, however, will be that of mucinous carcinoma rather than of usual borderline tumors of the ovary.