A giant cystic leiomyoma mimicking an ovarian malignancy

Introduction: Leiomyoma of the uterus is the most common type of tumor affecting the female pelvis and arises from uterine smooth muscle. The size of leiomyomas varies from microscopic to giant; giant myomas are exceedingly rare. We report an unusual case of a large, cystic, pedunculated uterine leiomyoma mimicking a primary malignant ovarian tumor on sonography and CT.

Presentation of case: A 58-year-old postmenopausal nulliparous woman presented with a history of lower abdominal pain and distension for a period of approximately 12 months. The patient's personal history revealed difficulty in walking, tiredness and recent weight gain of approximately 25kg. Sonography and CT examination showed a large mass that filled the abdomen. A preoperative diagnosis of a primary malignant ovarian tumor was made. The patient underwent laparotomy, total hysterectomy and bilateral salpingo-ooferectomy. The histology revealed a leiomyoma with extensive cystic degeneration.

Discussion: The current established management of uterine fibroids may involve expectant, surgical, or medical management or uterine artery embolization or a combination of these treatments. A surgical approach is preferred for management of giant leiomyomas.

Conclusion: Pedunculated leiomyomas should be considered in the differential diagnosis of a multilocular and predominantly cystic adnexal mass.