Benign metastasizing leiomyoma responsive to megestrol: case report and review of the literature.

Benign metastasizing leiomyoma (BML) is an unusual condition typically treated by surgical resection and hormonal therapy. A 37-year-old woman presented with dyspnea 6 years after uterine myomectomy. Computed tomographic scans showed pelvic and right-sided lung masses. Total abdominal hysterectomy and right salpingo-oophorectomy revealed only leiomyomas and benign ovarian cysts. Thoracotomy revealed multiple nodules consistent with leiomyomas. Estrogen and progesterone receptors on lung and uterine tissue were positive. A 21- x 18-mm residual area of neoplasm in the lung completely resolved 3 months after treatment with megestrol. The patient remains free of disease 3 years after lung resection. We present a rare case of BML in which the lung neoplasm responded to megestrol alone in the setting of intact ovarian function.