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

BACKGROUND: Intraabdominal fibromatosis is a rare tumor-like lesion of uncertain etiology. CASE: 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. CONCLUSION: Intraabdominal fibromatosis that expresses estrogen and progesterone receptors may respond favorably to treatment with aromatase inhibitors.