We present a case of a 46-year-old woman evaluated for abnormal uterine bleeding and an enlarged uterus, with normal endometrial sampling. Three months of leuprolide acetate injections resulted in a nonenlarging uterus and resolution of iron deficiency anemia and menorrhagia. Intraoperative examination suggested leiomyosarcoma, which was confirmed by postoperative permanent histologic sections. Residual uterine sarcomatous disease was confirmed on reexploration. Similar cases will continue to raise arguments against conservative hormonal intervention in the perimenopausal woman with an enlarged uterus. As the gynecologist gains familiarity with the use of gonadotropin-releasing hormone analogue therapy in the treatment of myomatous uteri, the criteria for hysterectomy will become less rigid and the potential for delay in the diagnosis and treatment of sarcomatous disease will become more common. Physicians must be cognizant of this potential complication of conservative therapy of leiomyomata uteri.