Multifocal tumorigenesis in the upper female genital tract--implications for staging and management.

A review of 128 cases of "primary" ovarian müllerian carcinoma treated at the King George V Memorial Hospital was undertaken to determine the relative frequency with which such tumors were associated with evidence of multifocal primary neoplasia. Of the 128 cases studied, 115 were invasive carcinomas and 13 were noninvasive or borderline ovarian tumors ("tumors of low malignant potential"). Eight of 10 borderline serous ovarian tumors (80%) and 37 of 75 invasive serous carcinomas (49%) exhibited evidence of independent primary neoplasia at more than one anatomical site in the biopsy material available for review. Many of these cases represented bilateral primary ovarian tumors, but autochthonous extraovarian neoplasia was also commonly encountered. A single borderline endometrioid ovarian tumor and six of 15 endometrioid carcinomas (40%) were associated with biopsy-proven multifocal primary tumorigenesis. These were predominantly neoplasms in one or both ovaries plus adenocarcinoma in the uterine corpus. Other histological types of malignant common epithelial tumors of the ovaries did not demonstrate any such tendency, highlighting major differences in pathogenesis between members of this loosely associated group of ovarian cancers. Our study suggests that gynecological endometrioid and serous malignancies are commonly multifocal and we feel this has significant implications for the way these neoplasms are staged and therefore treated.