These little inpoochings of the surface epithelium supposedly give rise to the "coelomic" family of ovarian tumors, i.e., serous, mucinous, clear-cell, endometrioid, Brenner.
Serous: recapitulate oviduct, papillary, cystic, psammoma bodies, more often bilateral, 90% malignant, tumor markers such as CA125 now used for screening.
Mucinous: recapitulate endocervix, cystic, more often unilateral, 90% benign, can become large National Enquirer tumor.
Endometrioid: Almost all malignant, recapitulate carcinoma of the endometrium, same risk factors.
Clear-Cell: Almost all malignant, look like renal cell carcinoma.
Brenner tumor: Almost all benign, balls of transitional-epithelial cells within a fibrous stroma. Coffee-bean nuclei if anyone asks (won't be me).
Main lecture slide page