"Primary peritoneal" high-grade serous carcinoma is very likely metastatic from serous tubal intraepithelial carcinoma: Assessing the new paradigm of ovarian and pelvic serous carcinogenesis and its implications for screening for ovarian cancer.

CONCLUSIONS: At least half the cases of primary peritoneal high-grade serous carcinoma are associated with intraepithelial carcinoma of the fallopian tube, usually involving the fimbriae. These findings support the view that, like "primary ovarian carcinoma," what has been traditionally classified as "primary peritoneal carcinoma" is probably derived from occult high-grade serous carcinoma in the fallopian tube. These findings have important implications for ultrasound screening trials for ovarian cancer which are based on the assumption that an enlarged ovary is a very early manifestation of disease.