Uterine smooth muscle tumors: the benign, the bizarre, and the deadly

August 1, 2006

Though most of these common tumors are benign, 0.5% of patients undergoing hysterectomy for presumed fibroids will be found to have a leiomyosarcoma, which usually kills within 5 years if it spreads outside the uterus. And five patients' leiomyosarcomas weren't diagnosed until after UAE.

Arising from the myometrium, uterine smooth muscle tumors include leiomyomata and leiomyosarcoma (LMS). As you well know, the [benign smooth muscle tumors classified as uterine leiomyomata-or fibroids-are common.] But how common? Using stringent pathologic evaluation, 77% of women undergoing hysterectomy were found to have fibroids.1 [In contrast, uterine LMS are clinically aggressive smooth muscle malignancies. They're rare,] accounting for only 1% of the more than 40,000 women diagnosed with uterine cancer last year.

Despite the rarity of these aggressive tumors, our goal here is to focus on them to a larger extent, after first briefly describing criteria and management options for benign fibroids. We'll also address controversies such as the potential for uterine artery embolization (UAE)-an increasingly popular choice in treating premenopausal women with fibroids-to delay the diagnosis of sarcoma. Other hotly debated sarcoma-related issues include lymph node evaluation, whether preserving ovaries adversely affects survival, and whether adjuvant chemotherapy or radiation is useful.

Identifying and managing leiomyomata

Drug and surgical treatment options. Ordinarily, initial therapy for leiomyomata is medicinal. An oral contraceptive pill sometimes improves menstrual symptoms. Often nonsteroidal anti-inflammatory drugs such as ibuprofen can effectively treat pain. Another option, long-term gonadotropin-releasing hormone (GnRH) agonists, is limited due to their hypoestrogenic effects. [And usually GnRH agonists don't shrink leiomyoma very much.2 However, these agents can be used to temporarily lessen menstrual bleeding and allow recovery in hematocrit prior to surgical intervention.]

If medical treatment fails, surgical intervention is often considered. Hysterectomy is considered definitive, but precludes future pregnancy, of course. Nondefinitive surgical management, including myomectomy and hysteroscopic resection, allows preservation of future fertility, but also holds a risk of recurrence. Myomectomy may be performed open or laparoscopically. The option of hysteroscopic resection is usually limited to submucosal leiomyomata. With increasing frequency, UAE is being used to treat symptomatic leiomyomata in premenopausal women.3,4