The challenge of leiomyosarcoma
The primary controversy surrounding morcellation of fibroid tissue specimens is the potential for undiagnosed malignancy, namely uterine leiomyosarcoma or endometrial stromal sarcoma. While other gynecologic malignancies, including cervical and endometrial cancers, are more common and potentially could be disseminated by morcellation, these cancers are more reliably diagnosed preoperatively with cervical and endometrial biopsies, and they do not tend to mimic benign diseases.
Epidemiology and risk factors. Uterine leiomyosarcoma is rare, with an estimated incidence of 0.36 per 100,000 woman-years.8 However, leiomyosarcoma can mimic the appearance and clinical course of benign fibroids, making preoperative diagnosis difficult. Risk factors for leiomyosarcoma include postmenopausal status, with a median age of 54 years at diagnosis, tamoxifen use longer than 5 years, black race, history of pelvic radiation, and certain hereditary cancer syndromes, such as Lynch syndrome.9-11 Because of these risk factors, preoperative evaluation is crucial to determine the most appropriate surgical method for removal of a large, fibroid uterus (see “Employ shared decision making”).
Estimated incidence at benign hysterectomy. The incidence of leiomyosarcoma diagnosed at the time of benign hysterectomy or myomectomy has been studied extensively since the FDA’s 2014 warning was released, with varying rates identified.11,12 The FDA’s analysis cited a risk of 1 in 498 for unsuspected leiomyosarcoma and 1 in 352 for uterine sarcoma.1 Notably, this analysis excluded studies of women undergoing surgery for presumed fibroids in which no leiomyosarcoma was found on pathology, likely inflating the quoted prevalence. The FDA and other entities subsequently performed further analyses, but a systematic literature review and meta-analysis by the Agency for Healthcare Research and Quality (AHRQ) in 2017 is probably the most accurate. That review included 160 studies and reported a prevalence of less than 1 in 10,000 to 1 in 770, lower than the FDA-cited rate.13
Prognosis. The overall prognosis for women with leiomyosarcoma is poor. Studies indicate a 5-year survival rate of only 55.4%, even in stage 1 disease that is apparently confined to the uterus.9 Although evidence is limited linking morcellation to increased recurrence of leiomyosarcoma, data from small, single-center, retrospective studies cite a worse prognosis, higher risk of recurrence, and shorter progression-free survival after sarcoma morcellation compared with patients who underwent en bloc resection.12,14 Of note, these studies evaluated patients who underwent uncontained morcellation of specimens with unsuspected leiomyosarcoma.
CASE Woman with enlarged, irregular uterus and heavy bleeding
A 40-year-old woman (G2P2) with a history of 2 uncomplicated vaginal deliveries presents for evaluation of heavy uterine bleeding. She has regular periods, every 28 days, and she bleeds for 7 days, saturating 6 pads per day. She is currently taking only oral iron therapy as recommended by her primary care physician. Over the last 1 to 2 years she has felt that her abdomen has been getting larger and that her pants do not fit as well. She is otherwise in excellent health, exercises regularly, and has a full-time job. She has not been sexually active in several months.
The patient’s vitals are within normal limits and her body mass index (BMI) is 35 kg/m2.Pelvic examination reveals that she has an enlarged, irregular uterus with the fundus at the level of the umbilicus. The exam is otherwise unremarkable. On further questioning, the patient does not desire future fertility.
What next steps would you include in this patient’s workup, including imaging studies or lab tests? What surgical options would you give her? How would your management differ if this patient were 70 years old (postmenopausal)?
Continue to: Perform a thorough preoperative evaluation to optimize outcomes...