The Cell of Origin of Ovarian Epithelial Tumors and the Ovarian Surface Epithelium Dogma: Does the Emperor Have No Clothes?

The widely favored hypothesis that ovarian epithelial tumors arise from the mesothelial cell layer lining the ovarian surface fails to explain the resemblance of these tumors to those arising in organs that are embryologically derived from the Müllerian ducts such as fallopian tubes, endometrium, and endocervix. In addition, this theory cannot account for the fact that tumors that are morphologically identical to ovarian carcinomas can sometimes be found outside the ovary. A suggestion is made that components of the secondary Müllerian system, which include paraovarian/paratubal cysts, rete ovarii, endosalpingiosis, endometriosis, and endomucinosis, merit some consideration as to their possible role in ovarian tumorigenesis.