Serous carcinoma is the most common type of ovarian cancer and usually is associated with peritoneal metastases and poor survival except for meticulously staged patients with tumors confined to the ovaries. Endometrioid and clear cell carcinomas account for most nonserous carcinomas and more often present with low-stage disease; survival for the various cell types is similar when stratified by stage. Borderline ovarian tumors can be subdivided into benign and malignant neoplasms, and in the view of some experts, this renders the borderline category obsolete. Women with typical serous borderline tumors (atypical proliferative serous tumors) constitute most of these patients and have virtually 100% survival, unless invasive peritoneal implants are present. Micropapillary serous carcinomas (a less common variant, also called serous borderline tumor with a micropapillary pattern) and tumors with invasive implants behave similar to low-grade invasive carcinomas.