Response of estrogen receptor-positive intraabdominal fibromatosis to aromatase inhibitor therapy.

Intraabdominal fibromatosis is a rare tumor-like lesion of uncertain etiology.A 49-year-old woman underwent abdominal hysterectomy and bilateral salpingooophorectomy in 1997 to treat uterine leiomyomata and ovarian fibromatosis. Postoperatively, she received estradiol 2 mg daily as hormone replacement therapy (HRT). In 2000, laparotomy performed for a large pelvic tumor revealed inoperable intraabdominal fibromatosis. The tumor, which was positive for estrogen and progesterone receptors, resolved during aromatase inhibitor therapy. The first follow-up computed tomographic (CT) scan revealed that the tumor masses were significantly reduced in size, and successive CT scans revealed stable disease.Intraabdominal fibromatosis that expresses estrogen and progesterone receptors may respond favorably to treatment with aromatase inhibitors.