Pathologic findings in eight cases of ovarian serous borderline tumors, three with foci of serous carcinoma, that preceded death or morbidity from invasive carcinoma.

We sought to assess the frequency of previously reported adverse histopathologic findings in ovarian serous borderline tumors (SBTs) in cases that preceded a patient's death or caused serious morbidity due to invasive carcinoma. SBTs with foci of invasive carcinoma that occupied a minority of the tumor and were associated with similar outcomes were also studied for potential additional insights. Eight cases were found over a 22-year period. Ten tumors in 5 patients were purely SBT; at initial staging, 1 patient had invasive peritoneal implants; 3 had noninvasive peritoneal implants; 1 was stage I. At last follow-up 3 of the 5 patients had died of carcinoma, 1 was alive with carcinoma, and 1 had no clinical evidence of disease 4 years after a sigmoid colectomy for invasive serous carcinoma of the bowel wall. Four tumors in 3 patients had foci of invasion that were more than microinvasive; at initial staging, all 3 patients had invasive peritoneal implants, and all died of carcinoma. All 14 of the ovarian tumors in the 8 cases had surface involvement by tumor cells, and in 8 tumors in 5 cases they were confined primarily to the ovarian surface. Foci of "micropapillary serous carcinoma" accompanied more obvious areas of infiltrative carcinoma in 2 of the 4 ovarian tumors, the peritoneal implants in 1 of the cases with purely SBTs, and a recurrence in this case and 1 other case. No morphologic finding in the 10 purely SBTs was predictive of subsequent malignant behavior. We conclude that extraovarian invasive serous carcinomas, either following or concurrent with an ovarian SBT, develop from borderline foci that may originate in the ovary, but frequently are likely to have arisen independently in the peritoneum. The carcinomas may be preceded or accompanied by noninvasive-appearing micropapillary foci in the peritoneum in some cases, but micropapillary foci in the ovarian tumors are infrequent and not a necessary antecedent.