Tubal origin of ovarian endometriosis and clear cell and endometrioid carcinoma

Current research has strongly proposed that contrary to prior beliefs, many ovarian epithelial cancers (OECs) do not, as their name suggests, originate in the ovaries. Recent findings regarding both high-grade and low-grade serous carcinomas has implicated the fallopian tube as a cell source for these OECs, but until now, there has been little insight into the cellular source for clear cell and endometrioid carcinomas. In this commentary review article, we aimed to discuss the new findings that support the possible contribution from the fallopian tube in clear cell and endometrioid carcinomas. Specifically, we have provided results that showcased ovarian surface epithelia (OSE) and ovarian epithelial inclusions (OEIs) as having mesothelial and tubal origins and have strongly recognized the secondary mullerian system and the ability for tubal epithelia to implant upon the ovarian surface as contributing to fallopian tube-derived OEIs (F-OEIs). We have provided initial indications of these F-OEIs and their relationship to endometriosis and then clear cell and endometrioid carcinomas and subsequently offer our new proposal of a probable tubal origin. This new proposal is a paradigm that drastically changes the understanding behind the origin of these OECs and has significant clinical implications in the near future.