We describe a case of multifocal polypoid endometriosis presenting with advanced bulky disease at a variety of pelvic sites. The extent of tumor and clinical features such as vaginal bleeding and pulmonary embolus were suggestive of a malignant process. Histopathology demonstrated glands that were neither crowded nor complex, with intervening fibromatous stroma that contained occasional endometrial stromal cells. These features were consistent with the newly described condition of polypoid endometriosis. Despite the endometrioid appearance of this tumor, there was florid ciliary cell change. An association has been suggested between polypoid endometriosis and prior tamoxifen use, although this patient had no history of prior hormone use.