BORDERLINE AND MALIGNANT MUCINOUS TUMORS OF THE OVARY. HISTOLOGIC CRITERIA AND CLINICAL BEHAVIOR

Abstract

The tremendous variation in length of survival of patients with mucinous cystadenocarcinoma of the ovary largely reflects the lack of uniform histologic criteria for the diagnosis. Evaluation of the efficacy of therapy for patients with Stage I carcinoma is especially difficult, since borderline tumors have been included that are histologically and clinically intermediate between a cystadenoma and a cystadenocarcinoma. A review of 688 primary mucinous tumors confined to one or both ovaries at the time of initial surgery indicated 80% were benign cystadenomas. The remaining 20% (136 neoplasms) were characterized by a proliferation of atypical epithelium that had features suggestive of malignancy. By analyzing the depth of stratification of the atypical cells and the presence or absence of stromal invasion, 97 Stage I borderline tumors (71%) were delineated from 39 Stage I cystadenocarcinomas (29%). Typically, the borderline tumor was a large, multilocular neoplasm that had papillary infoldings and two to three layers of atypical epithelial cells, but no invasion of the stroma. The “true” carcinoma had a greater degree of cellular stratification and/or unequivocal stromal invasion. An infiltrative growth pattern was identified in 56% of the carcinomas. Only 3 (4%) of 87 patients followed with a borderline tumor died with neoplasm compared to 9 (33%) of 27 patients followed with a cystadenocarcinoma. Rupture of tumor with spillage did not adversely affect the prognosis. Since the prognosis of the borderline mucinous tumor is vastly superior to that of a cystadenocarcinoma, the two should be separated if meaningful data on frequency, behavior, and therapeutic results are to be obtained. Our findings substantiate the rationale for preserving the contralateral uninvolved ovary in a young woman with a borderline mucinous ovarian tumor.