Uterine sarcoma in patients operated on for presumed leiomyoma and rapidly growing leiomyoma.

OBJECTIVE

To determine the incidence of uterine sarcoma in patients operated on for symptomatic uterine leiomyomas or "rapidly growing" leiomyomas.

METHODS

We reviewed the medical records of 1332 women admitted to either of two community hospitals between 1988-1992 for hysterectomy or myomectomy for uterine leiomyomas. The incidence of leiomyosarcoma, endometrial stromal sarcoma, and mixed mesodermal tumor was calculated. Patient ages, admitting symptoms, and operative and pathologic findings were analyzed. The study included 371 women (28%) operated on for rapidly growing leiomyomas. All patients operated on during the same interval and found to have a uterine sarcoma were reviewed.

RESULTS

One of the 1332 patients operated on for presumed leiomyoma was found to have a leiomyosarcoma. This women was the only patient found to have a sarcoma among 371 women operated on for rapid growth of the uterus. None of 198 patients who met a published definition of rapid growth had a uterine sarcoma. Two women (0.15%) had endometrial stromal sarcoma, but none had a mixed mesodermal tumor. During the same interval, nine additional patients were found to have uterine sarcomas, and for these women, the preoperative diagnosis was sarcoma in four, endometrial cancer in three, ovarian cancer in one, and prolapsed uterus in one.

CONCLUSIONS

The total incidence of uterine sarcoma (leiomyosarcoma, endometrial stromal sarcoma, and mixed mesodermal tumor) among patients operated on for uterine leiomyoma is extremely low (0.23%). The incidence of sarcoma among patients having surgery for "rapidly growing" leiomyoma (0.27%) or among those who met published criteria for rapid growth (0%) does not substantiate the concept of increased risk of sarcoma in these women.