Retroperitoneal leiomyoma of the uterus mimicking sarcoma in perimenopausal woman: case report.

Leiomyomas are very common benign tumors in the uterus and it is rare condition to present the retroperitoneal leiomyoma. The author reported a 48-year-old female patient who presented right pelvic mass with urinary incontinence and lower abdominal discomfort. Based on the preoperative imaging, provisional diagnosis was mesenchymal sarcoma. In the intraoperative findings, huge mass abutting to the uterus was observed in retroperitoneal space beneath the right broad ligament. After the exposure the retroperitoneal space, we encountered the well-demarcated tumor measuring 8 × 6 cm in diameter and this tumor attached the right surface of the uterus with fibrotic tissue. Pathologic findings demonstrated retroperitoneal uterine leiomyoma.