A 32-year-old woman has been attempting to become pregnant for the past 2 years without success. She also has had extremely painful menstrual cramping of many years' duration. An exploratory laparoscopy demonstrated multiple red-blue nodules covering the surface of her ovaries and uterine ligaments. These findings are most likely indicative of which of the following conditions?

Endometriosis, ectopic non-neoplastic endometrial tissue, is an impoant cause of infeility. The ectopic tissue replicates the cyclic endometrial changes during the menstrual cycle, including sloughing and bleeding. Such ectopic hemorrhage can result in pain, scarring, tubal obstruction, and infeility. Favored sites of endometriosis include pelvic ligaments, ovaries, and rectum. Endometrial hyperplasia can be a precursor to endometrial carcinoma and manifests with postmenopausal bleeding. Leiomyomas are benign tumors of the uterus that can also result in painful menses and can contribute to infeility.