Primary ovarian mucinous cystadenocarcinomas: a clinicopathologic study of 49 cases with long-term follow-up.

Prognostic data for ovarian mucinous carcinoma are limited and difficult to interpret because of differing diagnostic criteria and inclusion of secondary tumors. To better characterize these neoplasms, 49 primary ovarian mucinous tumors diagnosed as carcinoma by the Hart and Norris criteria and staged by the FIGO system were studied. Forty-four tumors (90%) were stage I, four were stage III and one was unstaged. Sixteen tumors (33%) were classified as intraglandular ("noninvasive") carcinoma; all were stage I and all patients were alive without tumor after 4-216 months (mean, 74 months); two patients had received adjuvant chemotherapy. Stromal invasion was present in the remaining 33 cases (67%), including 19 tumors with extensive invasion and 14 with one or more discrete foci of microinvasion (each focus < or = 1 mm). The microinvasive tumors were reclassified into intraglandular carcinoma with microinvasion (nine cases) and borderline (low malignant potential) tumor with microinvasion (five cases). All microinvasive tumors were stage I and none recurred after postoperative intervals of 9-176 months (mean, 71 months) for the microinvasive carcinomas and 33-117 months (mean, 60 months) for the microinvasive borderline tumors; only 1 of the 14 patients received adjuvant chemotherapy. All 19 extensively invasive carcinomas also had intraglandular carcinoma. Fourteen were stage I, four were stage III, and one was unstaged. Eleven (79%) of the stage I patients were alive without tumor after 10-220 months (mean, 110 months), including six who received chemotherapy; one was dead without tumor and two developed progressive disease (one had received adjuvant chemotherapy). The four extensively invasive stage III carcinomas were fatal after 1-59 months. The unstaged patient received adjuvant chemotherapy and was alive without recurrence at 98 months. Conclusions of this study are as follows: (1) primary mucinous carcinomas are very uncommon tumors, after rigorous exclusion of metastatic carcinomas and tumors associated with pseudomyxoma peritonei; (2) bilaterality is not a feature of primary mucinous carcinomas; (3) FIGO stage is the single most important prognostic factor, with stage I carcinomas having a very favorable prognosis; (4) stage I carcinomas that metastasize have extensive stromal invasion; (5) extensive stromal invasion is found only in tumors with a component of intraglandular carcinoma; (6) high-stage carcinomas invariably contain extensively invasive carcinoma and have a very poor prognosis; and (7) stromal microinvasion with individual foci not exceeding 1 mm does not appear to be an adverse factor in either carcinomas or borderline tumors of stage I.