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Disclosures: Elizabeth A Stewart, MD Grant/Research/Clinical Trial Support: InSightec [Uterine fibroids (ExAblate)]. Consultant/Advisory Boards: Gynesonics [Uterine fibroids (VizAblate)]; Abbott/AbbVie [Uterine fibroids (Leuprolide acetate)]; Bayer [Uterine fibroids]; GlaxoSmithKline [Uterine fibroids and adenomyosis]. Robert L Barbieri, MD Nothing to disclose. Barbara Goff, MD Nothing to disclose. Tommaso Falcone, MD, FRCSC, FACOG Nothing to disclose. Sandy J Falk, MD Employee of UpToDate, Inc.
Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence.
INTRODUCTION — Benign uterine leiomyomas (fibroids) are the most common pelvic tumor in women (estimated lifetime risk of 70 percent in white women and 80 percent in black women) [1-3]. Uterine sarcoma is rare (3 to 7 per 100,000 in the United States population) with a poor prognosis .
Clinicians who are evaluating a woman with presumed leiomyomas are presented with the clinical challenge of deciding which rare patients may have sarcoma. While there are differences in the populations of the two disorders, there is some overlap. There are several histologic types of uterine sarcoma. The main type of sarcoma that may resemble a leiomyoma is leiomyosarcoma, which presents as a myometrial mass. In contrast, endometrial stromal sarcoma presents as an endometrial mass. However, this could potentially have a similar appearance to a submucosal leiomyoma.
Historically, hysterectomy was the mainstay of treatment for women with a uterine mass, and uterine sarcoma, if present, was identified by pathologic analysis. In current practice, women with presumed benign leiomyomas are treated with a variety of medical and conservative surgical or interventional procedures. Non-excisional therapies for fibroid-related symptoms (eg, hormonal contraception, endometrial ablation, interventional radiology procedures) do not produce specimens for pathologic examination. Thus, the diagnosis of malignant disease may be missed. In addition, procedures or techniques that disrupt a uterine mass (ie, myomectomy, or hysterectomy, especially when the specimen is morcellated) may disseminate malignant cells. Equally important priorities, however, are to avoid unnecessary surgery for the purpose of excluding the rare sarcoma and offering the option of minimally invasive approaches in low-risk patients.
Approaches to differentiating benign uterine leiomyomas from uterine sarcoma are reviewed here. General principles of the diagnosis of uterine leiomyomas, the diagnosis and treatment of uterine sarcoma, and benign and atypical leiomyoma variants are discussed separately. (See "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)" and "Uterine sarcoma: Classification, clinical manifestations, and diagnosis" and "Treatment and prognosis of uterine leiomyosarcoma" and "Variants of uterine leiomyomas (fibroids)" and "Classification and treatment of endometrial stromal tumors".)
DIFFERENTIAL DIAGNOSIS OF A UTERINE MASS — The challenge of differentiating a leiomyoma from a uterine sarcoma is one part of the diagnostic process for all women with a uterine mass. The differential diagnosis of an enlarged uterus includes both benign and malignant conditions:
●Uterine adenomyoma or diffuse adenomyosis
●Uterine carcinosarcoma (considered an epithelial neoplasm)
●Metastatic disease (typically from another reproductive tract primary)
The differential diagnosis of an enlarged uterus is discussed in detail separately. (See "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)", section on 'Differential diagnosis'.)
PREVALENCE OF SARCOMA AFTER SURGERY FOR PRESUMED LEIOMYOMAS — Uterine sarcoma is rare (3 to 7 per 100,000 United States women, as noted above) . The rate of sarcoma in women with a symptomatic uterine mass is higher, but the true prevalence is unknown.
Unfortunately, there are no high quality data regarding the prevalence of sarcoma in women planning surgery for presumed benign leiomyomas. The available studies, which document the prevalence of sarcomas in women with myometrial mass(es), are retrospective case series. Additional limitations of these studies include: many were conducted at referral centers, and so may include complex cases; preoperative evaluation with imaging and endometrial sampling was not performed in all patients; imaging techniques may have been less advanced in earlier studies; some studies included women diagnosed with sarcoma preoperatively (usually with endometrial sampling), so these were not intra- or postoperative diagnoses; and some women with sarcoma had known risk factors (eg, older age, postmenopausal status).
In studies of women undergoing hysterectomy or myomectomy for a myometrial mass, the prevalence of sarcoma is approximately 0.20 percent (1 in 500) in most studies, and estimates of the prevalence range from 0.1 (1 in 1000) to 0.28 percent (1 in 352), depending upon which studies are included or excluded [5-19]. The majority of cases reported were leiomyosarcoma, but these studies included a few cases of endometrial stromal sarcoma. The prevalence of leiomyosarcoma is therefore likely slightly higher.
A report from a United States insurance database, including 232,882 women who underwent minimally invasive (laparoscopic or robotic ) hysterectomy, found that morcellation was performed in 36,470 (15.7 percent) . Among the women who had morcellation, there were 99 cases of uterine cancer (0.27 percent; 1 in 370); 39 uterine neoplasms of uncertain malignant potential; 368 cases of endometrial hyperplasia (most cases were without atypia ); and 26 other gynecologic malignancies. The prevalence of malignancy was 0.34 percent and of all neoplastic conditions was 1.5 percent, although the clinical significance of endometrial hyperplasia without atypia is uncertain. Malignant disease was associated with increasing age; compared with women age 40 years, the prevalence ratios were: 50 to 54 years, 4.97; 55 to 59, 19.37; 60 to 64, 21.36; and ≥65, 35.97. In absolute numbers, the prevalence of cancer in this series for women under age 40 was 1/1500 and for women 40 to 44 was 1/1100. A limitation of the study was that the histology of the uterine cancer cases was not reported. These data add support to limiting morcellation to premenopausal women, since 50 years old is approximately the average age of menopause. (See 'Do morcellation, myomectomy, or supracervical hysterectomy worsen prognosis?' below.)
CLINICAL CHARACTERISTICS — Assessing clinical characteristics is the initial approach to evaluating a patient with a presumed leiomyoma in whom there is some concern of uterine sarcoma. Suspicion of sarcoma may change based upon a patient’s risk factors or response to treatment. Unfortunately, the clinical manifestations of benign leiomyomas and uterine sarcomas are often indistinguishable.
Risk factors — Uterine sarcoma is rare and risk factors are not well defined for sarcomas in general or specifically for leiomyosarcoma. The known risk factors are summarized below and discussed in detail separately. (See "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Epidemiology'.)
Common to both leiomyomas and sarcoma
Race — Black race is a risk factor for both uterine leiomyomas and uterine sarcoma. The relative risk and incidence of fibroids is two- to three-fold greater in black women than in white women. The cumulative incidence of fibroids of any size, including very small tumors, by age 50 years is >80 percent for black women and almost 70 percent for white women . (See "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)", section on 'Prevalence'.)
Similarly, black women have an approximately two-fold higher incidence of leiomyosarcomas (but not other types of uterine sarcoma) and carcinosarcoma than white women . (See "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Race'.)
Increasing age and postmenopausal status — Benign leiomyomas develop primarily in women of reproductive age, with symptoms developing on average as early as the 20s in black women and typically in the 30s or 40s in white women. Fibroids typically stabilize or diminish in size following menopause. Postmenopausal estrogen therapy may be associated with modest growth of myomas and/or persistent symptoms, but does not appear to induce the development of new fibroids. (See "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)", section on 'Prevalence' and "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)", section on 'Women on hormone therapy'.)
In contrast, increasing age is a significant risk factor for uterine sarcomas. The average age at diagnosis is 60 years; thus, the majority of sarcomas occur after menopause. Young age does not exclude the diagnosis of uterine sarcoma, however, since it has been reported in women as young as their mid-20s . (See "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Epidemiology'.)
Thus, particularly for postmenopausal women, a new or growing uterine mass warrants further evaluation for uterine sarcoma. The level of suspicion may be lower in women who are on postmenopausal estrogen therapy and have a small increase in the size of a fibroid known to present prior to menopause. In this subgroup, stopping postmenopausal estrogen therapy is also an option to see if regression occurs. (See "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)", section on 'Women on hormone therapy'.)
The available evidence supports an increased risk of undetected malignancy in women 50 years or older who undergo morcellation of uterine tissue . (See 'Prevalence of sarcoma after surgery for presumed leiomyomas' above.)
Tamoxifen — Long-term use of tamoxifen (five years or more) is associated with an increase in risk of developing uterine sarcoma. The absolute risk remains small (approximately 17 per 100,000 women) . In general, sarcomas present two to five years following the start of tamoxifen therapy and are often at an advanced stage at diagnosis [24,25]. (See "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Tamoxifen'.)
Other risk factors — Other risk factors that are associated with uterine sarcoma, but not with leiomyomas, include pelvic irradiation, a history of childhood retinoblastoma, and hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome. (See "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Pelvic radiation' and "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Hereditary conditions'.)
Data are inconclusive regarding parity and time of menarche and menopause as risk factors for sarcoma. For benign leiomyomas, early menarche (<10 years old) is a risk factor (particularly in black women) and parity decreases the chances of fibroid formation. (See "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)", section on 'Prevalence' and "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Other risk factors'.)
Clinical manifestations — Abnormal uterine bleeding, pelvic pain/pressure, and a pelvic mass are the primary presenting symptoms and signs for both leiomyomas and sarcoma, making it difficult to differentiate between the two on this basis [22,26-28]. Some women with sarcoma present with a foul-smelling vaginal discharge, but this is not a reliable indicator of malignancy since vaginal discharge is a common gynecologic symptom. (See "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)", section on 'Clinical manifestations' and "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Clinical presentation'.)
Clinical manifestations associated with metastatic disease may be found in women with sarcoma, but not with ordinary leiomyomas. Uterine sarcomas spread via intraabdominal, lymphatic, or hematogenous routes. Hematogenous spread is most often to the lungs. Of note, some benign leiomyoma variants also disseminate and must be excluded if widespread disease is found. (See "Variants of uterine leiomyomas (fibroids)", section on 'Benign uterine variants with extrauterine disease' and "Treatment and prognosis of uterine leiomyosarcoma" and "Classification and treatment of endometrial stromal tumors", section on 'Evaluation of suspected disease'.)
Failure to respond to treatment — Failure to respond to medical treatment (gonadotropin-releasing hormone [GnRH] agonist treatment) or non-excisional procedures such as uterine artery embolization for leiomyomas has preceded a diagnosis of malignancy in multiple reports [29-35]. However, such treatment failures are not definitive evidence of malignancy.
The concept of failure to respond to hormonal treatment has been proposed as a method of differentiating between uterine leiomyomas and sarcoma. This approach has not proved useful, however, since the few data regarding this approach are mixed, with one report of shrinkage in a leiomyosarcoma .
While it is possible that failure to respond to other nonexcisional therapies such as magnetic resonance guided focused ultrasound surgery (MRgFUS) also raises the possibility of sarcomas, the only report to date led to surgery rather than MRgFUS for a suspected sarcoma due to suspicious pretreatment imaging .
DIAGNOSTIC METHODS — The diagnosis of uterine sarcoma is based upon histologic examination. Uterine sarcomas are most commonly diagnosed following myomectomy or hysterectomy for presumed leiomyomas.
Preoperative and intraoperative findings are of limited value in estimating the likelihood that a mass is a uterine sarcoma. Magnetic resonance imaging (MRI) and endometrial sampling are the most potentially useful techniques.
Pelvic examination — A thorough pelvic examination should be performed in all women with a pelvic mass. The size, contour, and mobility of the uterus should be noted, along with any other findings (eg, adnexal mass, cervical mass, or vaginal nodules). These findings are helpful to follow changes in the uterus over time and/or to aid surgical planning. Unfortunately, however, there are no examination findings that distinguish a leiomyoma from a uterine sarcoma.
Choice of imaging modality — There is no pelvic imaging modality that can reliably differentiate between benign leiomyomas and uterine sarcomas. Leiomyomas and uterine sarcomas appear similar; both are focal masses within the uterus and both often have central necrosis.
Pelvic ultrasound is typically the first-line study to evaluate women for potential uterine pathology. Sonographic evaluation of a uterine mass may identify features suggestive of sarcoma (mixed echogenic and poor echogenic parts, central necrosis, and color Doppler findings of irregular vessel distribution, low impedance to flow, and high peak systolic velocity); however, many of these characteristics may also be found in benign leiomyomas .
MRI may be helpful in women in whom there is a suspicion of sarcoma; however, it does not provide a definitive diagnosis. High signal intensity is not a reliable indicator of uterine sarcoma . A consistent finding in leiomyosarcomas is the absence of calcifications. Some data suggest that ill-defined margins are consistent with a sarcoma . Two small studies using different techniques of MRI with gadolinium contrast have reported specificities of 93 to 100 percent and positive predictive values of 53 to 100 percent [39,40]. Further study of use of MRI for this purpose is needed.
Computed tomography (CT) does not reliably differentiate between leiomyomas and uterine sarcomas .
Positron emission tomography/CT with fluorodeoxyglucose (FDG) does not appear to be useful to distinguish between leiomyomas and uterine sarcomas. While the FDG uptake is generally high in sarcomas and low in leiomyomas, the uptake varies across individual tumors .
Despite the limitations of pelvic imaging, however, we suggest that women with a pelvic mass that is newly diagnosed or has changed markedly in size or mobility undergo a pelvic ultrasound as an initial imaging study to exclude other etiologies of uterine enlargement. If uterine sarcoma is suspected based upon clinical characteristics of the patient or mass or upon sonographic findings, MRI with gadolinium contrast may aid in assessing the likelihood of malignancy.
Findings that do NOT reliably predict sarcoma
Rapidly growing uterine mass — The common teaching has been that rapid growth of a uterine mass (eg, increasing by six weeks’ gestational size within one year ) is a sign of a potential uterine sarcoma. However, it appears that most women with a rapidly enlarging uterus or uterine mass do NOT have a sarcoma.
This concept of a rapidly growing uterine mass as a sign of a potential sarcoma appears to date back to the era when pelvic examinations alone were used to assess uterine size . With modern pelvic imaging, there is an increased appreciation that, in women of reproductive age, leiomyomas both grow and shrink, and do so at differing rates within the same woman [44-47]. As an example, in a prospective study, 101 fibroids in 36 women were evaluated with MRI at three-month intervals for one year . Increase in volume of ≥30 percent in a three-month period was found in 37 myomas; rapid growth was more likely in tumors that were ≤5 cm in diameter. (See "Epidemiology, clinical manifestations, diagnosis, and natural history of uterine leiomyomas (fibroids)", section on 'Natural history'.)
Rapid growth may occur in either a sarcoma or a benign leiomyoma. In addition, it is theoretically possible for a sarcoma to remain indolent for a long period of time and only come to diagnostic attention when a more aggressive phase of disease is entered.
The teaching about rapid growth of a uterine mass being associated with an increased risk of uterine sarcoma was not substantiated in a study of 1332 women who underwent hysterectomy or myomectomy of presumed uterine leiomyomas . The incidence of uterine sarcoma was low for all women, with a similar incidence in the 371 women with a rapidly growing uterus by clinical or ultrasound examination (1 uterine sarcoma; 0.27 percent) and in the 961 without rapid uterine growth (2 uterine sarcomas; 0.15 percent). In addition, a literature review of 26 studies found that a history of rapid uterine enlargement was documented in only 15 of 580 patients (2.6 percent) with uterine sarcoma . Thus, the great majority of premenopausal women with a rapidly enlarging uterus or uterine mass do not have a sarcoma. Moreover, research on normal leiomyomas show that growth of up to 138 percent can occur within six-months .
In contrast, postmenopausal women who have a uterine mass that is new or is growing at either a slow or rapid pace should be evaluated for malignancy. The level of suspicion for uterine sarcoma is lower in women who are on postmenopausal estrogen therapy and have a small increase in the size of a presumed fibroid known to have been present prior to menopause. (See 'Increasing age and postmenopausal status' above.)
Large or solitary uterine mass — Retrospective studies have reported that a sarcoma is often the largest (or the only) mass within a uterus, averaging 7 to 9 cm in diameter [22,26,48,49]. However, leiomyomas may also be singular and may be of any size. Although data are limited, large uterine size (in excess of 20 gestational weeks) has also not been shown to be associated with sarcoma risk [22,50]. As a result, these features are not useful in identifying malignancy.
Biopsy — Endometrial sampling can detect some uterine sarcomas. Preoperative imaging-guided biopsy is generally not performed, but intraoperative biopsy is indicated if there are suspicious findings during surgery.
Endometrial sampling — Endometrial sampling yields a preoperative diagnosis in some women with uterine sarcoma [51,52]. There are few data regarding use of endometrial sampling in women with sarcoma, and only two small studies have reported the sensitivity of preoperative endometrial sampling for a diagnosis of leiomyosarcoma. In one study, among women with leiomyosarcoma, three of eight (38 percent]) who underwent preoperative sampling had a correct diagnosis . In another study, the sensitivity for a diagnosis of leiomyosarcoma was four of six (67 percent), but two additional women with leiomyosarcoma had preoperative pathology results that reported malignant disease, but an incorrect histologic diagnosis (one endometrial carcinoma, one other sarcoma ). Thus, these women would have been managed surgically as appropriate for a malignancy. In addition, in the same study, the sensitivity for a diagnosis of endometrial stromal sarcoma was two of six women (33 percent), and the pathology results in the remaining four women were negative. (See "Uterine sarcoma: Classification, clinical manifestations, and diagnosis", section on 'Biopsy'.)
Since endometrial biopsy is a minimally invasive procedure and is already indicated in many women with abnormal uterine bleeding to exclude endometrial neoplasia, we suggest sampling in women in whom sarcoma is suspected or for whom the planned procedure includes intraperitoneal morcellation, which would disrupt the specimen and potentially disseminate malignant tissue. (See 'Do morcellation, myomectomy, or supracervical hysterectomy worsen prognosis?' below.)
Other biopsy techniques — Infrequently, a uterine sarcoma will prolapse through the cervix and can be biopsied .
Use of minimally invasive needle biopsy of a uterine mass (guided by pelvic imaging or laparoscopy) has been proposed, but is not typically performed. Limitations of this method are that the accurate diagnosis of sarcoma requires sampling of multiple sites and that the procedure may spill malignant cells within the peritoneal cavity.
Intraoperative evaluation — During myomectomy, some tumor characteristics may raise suspicion of malignancy. Frozen section analysis cannot definitively diagnose or exclude uterine sarcoma.
Gross characteristics of the mass — During excisional surgery, uterine sarcomas may appear or feel different than leiomyomas. Potential features of sarcomas compared with leiomyomas include (picture 1) [54-56]:
●Loss of the typical whorl pattern
●Absence of a bulging surface when the capsule is incised
●Ill-defined margins – The mass may be difficult to excise, although this may also be true of an adenomyoma or certain leiomyomas (eg, due to degenerative change or prior treatment with a gonadotropin-releasing hormone [GnRH] agonist or antagonist).
Detection of such characteristics may raise the suspicion of a sarcoma, but should not be the sole reason for proceeding with an unplanned hysterectomy. These differences are subtle, and their identification relies upon adequate surgical experience with ordinary leiomyomas.
Frozen section — Frozen section analysis is not reliable for excluding uterine sarcoma [8,26]. Multiple areas must be sampled to obtain an accurate diagnosis, while frozen section analysis typically depends upon a limited tissue sample. Thus, there is a high likelihood of a false negative result even if a sarcoma is present. Only a definitive diagnosis of sarcoma on frozen section should influence surgical decisions (eg, whether to perform hysterectomy or staging). (See 'Should unplanned hysterectomy be performed based on intraoperative findings?' below.)
Postoperative pathologic evaluation — Three criteria are important to the diagnosis of uterine sarcomas: mitotic index, cellular atypia, and geographic areas of coagulative necrosis separated from viable tumor [56,57]. The more features exhibited by the lesion, the more likely it is to have clinically aggressive behavior [56,57]. There are a number of pathologic entities in which lesions display some, but not all, of the facets of malignancy. (See "Variants of uterine leiomyomas (fibroids)", section on 'Smooth muscle tumors of uncertain malignant potential'.)
Diagnosis requires examination of multiple sites in the mass . Features of the gross appearance of the tissue, including the color, consistency, and variegation of the incised surface, can help guide sampling of tissue for microscopic examination.
Do morcellation, myomectomy, or supracervical hysterectomy worsen prognosis? — Techniques such as myomectomy, intraperitoneal morcellation (cutting tissue into pieces to remove through a small incision), and supracervical hysterectomy disrupt a uterine specimen. Infrequently, an occult uterine cancer is diagnosed postoperatively and, in such cases, there is a concern that malignant cells may have been disseminated or remain in uterine or cervical tissue that was not removed. In addition, dissemination of benign leiomyomatous tissue may result in benign disseminated tissue implants that require further treatment . Another concern is that the morcellated specimen is more difficult for pathologists to evaluate. (See "Variants of uterine leiomyomas (fibroids)".)
Disruption of the specimen appears to worsen prognosis of uterine cancer, but there are few data and the risk of the specific surgical methods (power morcellation, scalpel morcellation, supracervical hysterectomy, abdominal or hysteroscopic myomectomy) compared with each other is uncertain [16,59-62].
There is no reliable method to distinguish uterine sarcoma from benign leiomyomas preoperatively, as discussed in detail above. Among women planning surgery for one or more uterine masses that are presumed to be benign leiomyomas, the prevalence of uterine sarcoma is less than 1 in 323. One approach is to avoid morcellation in women with risk factors for uterine sarcoma; however, the efficacy of this strategy to decrease the risk of morcellation of a sarcoma has not been evaluated. Moreover, use of a more invasive procedure such as laparotomy may increase surgical morbidity . (See 'Prevalence of sarcoma after surgery for presumed leiomyomas' above.)
In addition to uterine sarcoma, there is concern about morcellation of uterine smooth muscle tumors of uncertain malignant potential or other uterine malignant or premalignant conditions (endometrial carcinoma, endometrial hyperplasia, carcinosarcoma). Endometrial carcinoma or hyperplasia is typically diagnosed preoperatively, since endometrial sampling is a simple and effective diagnostic method and should be performed in all women preoperatively if indicated (table 1). However, unsuspected endometrial carcinoma is occasionally diagnosed postoperatively, particularly in asymptomatic women and in those who undergo hysterectomy for indications other than a uterine mass (eg, pelvic organ prolapse) [64-67]. (See "Endometrial sampling procedures".)
Comparative studies have reported that morcellation is associated with a worse prognosis for women with uterine sarcoma [16,59-61]. However, there are few data and the available studies often include different methods of morcellation, as well as myomectomy. As an example, one retrospective cohort study of women with uterine leiomyosarcoma apparently confined to the uterus at time of surgery included 25 women who underwent abdominal, vaginal, or laparoscopic morcellation and 31 who did not. The study found that morcellation was associated with a significant decrease in five-year disease-free survival (40 versus 65 percent) and overall survival (46 versus 73 percent) . In addition, data from another retrospective study of women with disease confined to the uterus at presentation (16 had morcellation; 52 did not) found that morcellation was associated with a significant decrease in the median time to recurrence (10.8 versus 25.7 months) and a 2.8-fold increase in the risk of recurrence .
Regarding supracervical hysterectomy, a small study of women with endometrial carcinoma or uterine sarcoma found that 12 patients who underwent supracervical hysterectomy were not upstaged, while 2 of 5 patients who underwent power morcellation (along with myomectomy or hysterectomy) were upstaged from stage I to stage III .
The concerns about uterine morcellation potentially impacts women who undergo surgery for presumed benign leiomyomas. Counseling of women with presumed uterine fibroids includes discussion of all available treatment options and appropriate assessment for endometrial carcinoma and uterine sarcoma, including evaluation for current disease and risk factors. Because a preoperative diagnosis of sarcoma is uncommon, morcellation of a malignant tumor may occur even in low-risk women. A woman’s treatment options, preference, and risk factors for uterine sarcoma should be considered when deciding upon a surgical approach and weighed against the benefits of alternative approaches. (See 'Risk factors' above.)
Surgical techniques that disrupt the uterine specimen should not be performed in women with known or suspected uterine or other gynecologic cancer. For women with a uterine mass who are undergoing laparoscopic hysterectomy or myomectomy and who have risk factors for uterine sarcoma (eg, postmenopausal status, history of ≥2 years of tamoxifen therapy, history of pelvic irradiation, history of childhood retinoblastoma, or personal history of hereditary leiomyomatosis and renal cell carcinoma [HLRCC] syndrome), we suggest NOT using power morcellation of uterine tissue with the potential for intraperitoneal dissemination.
If a surgical option using power morcellation is elected, counselling and informed consent should explicitly include the risk of dissemination of malignant cells if a malignancy is incidentally detected [68-71]. In cases in which the postoperative pathology shows malignancy, the patient should be referred to a gynecologic oncologist for further evaluation and treatment as soon as possible.
Use of power morcellation is an ongoing area of debate and investigation and further practice modifications may continue to evolve. The approaches to this issue include:
●Use of minimally invasive approaches that do not require power morcellation, including removal of an intact surgical specimen via mini-laparotomy or the vaginal cuff (following vaginal hysterectomy or total laparoscopic hysterectomy) .
●Some surgeons use techniques to contain uterine tissue in a laparoscopic bag and morcellate in the bag to attempt to avoid tumor dissemination [72-77]. The safety and efficacy of use of a laparoscopic bag require further study. One concern regarding this approach is the ability to visualize the tissue being morcellated and surrounding structures to avoid damage by the morcellator blade. In addition, if the bag is disrupted by the morcellator blade or by the insertion of ports or instruments, tissue may be disseminated. Some institutions allow use of these methods only as part of research protocols. Use of a laparoscopic bag with morcellation is also used by other surgical specialties. (See "Instruments and devices used in laparoscopic surgery", section on 'Tissue bags'.)
●Laparotomy is an option, but is associated with a larger incision, more postoperative pain, a longer recovery period, and potentially more complications than minimally invasive approaches .
In response to concerns about dissemination of malignant tissue with power morcellation, some institutions in the United States have suspended use of power morcellation in women with uterine masses while this issue is studied. Other institutions and the American College of Obstetricians and Gynecologists (ACOG) and the American Association of Gynecologic Laparoscopists (AAGL) have affirmed that, when used in properly selected and informed patients, morcellation provides a benefit of allowing a minimally invasive surgical approach [18,71]. One device manufacturer has suspended sales of a power morcellator and recalled all morcellator devices [78,79].
Use of morcellation in other surgical specialties is discussed separately. (See "Instruments and devices used in laparoscopic surgery", section on 'Morcellators'.)
Professional society and FDA statements — The risk of a dissemination of malignant cells in women with an incidental finding of malignancy associated with power morcellation of uterine tissue has been the focus of review and statements by ACOG, AAGL, Society of Gynecologic Oncology (SGO), and the US Food and Drug Association (FDA) [5,18,68,71]. All of these statements emphasize the importance of several key preoperative steps when morcellation is planned, including: appropriate evaluation for uterine and cervical cancer, assessment for uterine sarcoma risk factors, and informed consent regarding the risk of tumor dissemination. In addition, all organizations have acknowledged the need to gather more data regarding the risks of morcellation.
The ACOG statement addresses both the risks and benefits of morcellation; the following are excerpts :
●Minimally invasive surgery, including with power morcellation, continues to be an option for some patients when performing hysterectomy and myomectomy. At the same time, it is critical to minimize the risk for patients undergoing these surgeries who may have an occult gynecologic cancer.
●Without power morcellation, some patients may be ineligible for minimally invasive gynecologic surgery (eg, supracervical hysterectomy).
The use of power morcellation in laparoscopic hysterectomy and myomectomy in women with uterine fibroids is discouraged by the FDA. The FDA issued a safety communication in April, 2014 with the following recommendations :
●Be aware that based on currently available information, the FDA discourages the use of laparoscopic power morcellation during hysterectomy or myomectomy for the treatment of women with uterine fibroids.
●Do not use laparoscopic uterine power morcellation in women with suspected or known uterine cancer.
●Carefully consider all the available treatment options for women with symptomatic uterine fibroids.
●Thoroughly discuss the benefits and risks of all treatments with patients.
●For individual patients for whom, after a careful benefit-risk evaluation, laparoscopic power morcellation is considered the best therapeutic option:
•Inform patients that their fibroid(s) may contain unexpected cancerous tissue and that laparoscopic power morcellation may spread the cancer, significantly worsening their prognosis.
•Be aware that some clinicians and medical institutions now advocate using a specimen “bag” during morcellation in an attempt to contain the uterine tissue and minimize the risk of spread in the abdomen and pelvis.
Further steps by the FDA are:
●Instruct manufacturers of power morcellators used during laparoscopic hysterectomy and myomectomy to review their current product labeling for accurate risk information for patients and providers;
●Will convene a public meeting of the Obstetrics and Gynecological Medical Device Advisory Committee to discuss: 1) the clinical role of laparoscopic power morcellation in the treatment of uterine fibroids, 2) whether surgical techniques and/or use of accessories, such as morcellation/specimen bags, can enhance the safe and effective use of these devices, and 3) whether a “boxed warning” related to the risk of cancer spread should be required for laparoscopic power morcellators;
●Will continue to review adverse event reports, peer-reviewed scientific literature, and information from patients, healthcare providers, gynecologic and surgical professional societies, and medical device manufacturers.
Should hysterectomy be performed to exclude uterine sarcoma? — For most women with presumed uterine leiomyomas, whether asymptomatic or symptomatic, we recommend not performing hysterectomy for the sole purpose of excluding malignancy. Reasonable exceptions to this are women with endometrial sampling and/or magnetic resonance imaging (MRI) results that strongly suggest sarcoma, those with thoracic imaging consistent with lung metastases, those with constitutional symptoms suggestive of malignancy, or those with multiple risk factors for uterine sarcoma.
The best clinical estimate of the likelihood of uterine sarcoma depends upon a constellation of factors. Unfortunately, preoperative and intraoperative findings are of limited value in diagnosing a uterine sarcoma. Factors that may raise a suspicion of sarcoma include symptoms, risk factors, failure of response to prior therapy, and the findings of MRI and endometrial sampling. (See 'Risk factors' above and 'Failure to respond to treatment' above and 'Choice of imaging modality' above and 'Endometrial sampling' above.)
In the rare cases in which a woman presents with a uterine mass and symptoms of lung lesions (eg, dyspnea), evidence of lung metastases on thoracic imaging greatly increases the likelihood of a malignant process. However, benign metastasizing leiomyomas is a benign condition that may also present with lung lesions. (See "Variants of uterine leiomyomas (fibroids)", section on 'Benign metastasizing leiomyomas'.)
Asymptomatic women — Hysterectomy should not be performed in most women with asymptomatic presumed leiomyomas for the sole purpose of excluding a uterine sarcoma.
The most important factor in such decisions is the rarity of uterine sarcoma. The likelihood of finding sarcoma in women with a preoperative diagnosis of leiomyomas has been consistently reported in observational studies of 1000 or more women as approximately 0.2 percent [6-15]. These data are from symptomatic women, so the risk is likely much lower in asymptomatic women. This risk is much lower than the risk of severe complications associated with hysterectomy (3.5 to 11.0 percent) for benign disease found in studies of 1000 to 30,000 hysterectomies [80,81]. This recommendation is in agreement with ACOG, which advises that there is insufficient evidence to support hysterectomy for asymptomatic leiomyomas solely to rule out malignancy .
Given these data, the risk of a missed diagnosis of sarcoma in a small number of women does not appear to outweigh exposing significantly more women to the risks of unnecessary hysterectomy. In our practice, the primary exceptions we make to this are for women in whom endometrial sampling and/or MRI strongly suggests sarcoma or those with thoracic imaging consistent with lung metastases. Hysterectomy is also a reasonable option for women with multiple risk factors for uterine sarcoma. (See 'Risk factors' above and 'Choice of imaging modality' above and 'Endometrial sampling' above.)
Following the detection of presumed uterine fibroids in an asymptomatic woman, there are no high quality data to guide follow-up. We order an initial imaging study (usually an ultrasound) to confirm that a pelvic mass is consistent with a fibroid rather than with other etiologies (eg, ovarian mass). After this initial evaluation, we perform annual pelvic examinations. If the characteristics of the uterus change or symptoms develop, we proceed with further evaluation and patient counseling regarding treatment options. (See "Overview of treatment of uterine leiomyomas (fibroids)", section on 'Expectant management'.)
Symptomatic women — For women with symptomatic presumed leiomyomas, hysterectomy is one of several treatment options. The best treatment option should be chosen based upon the patient’s symptoms, findings on evaluation, plans for future pregnancies, and patient preferences.
The advantage of hysterectomy is that it is a definitive procedure, but the disadvantages are loss of fertility, risk of surgical complications, the time needed for recovery, and risk of long-term morbidity, especially if the ovaries are removed at the time of hysterectomy [83-85]. In some women, the question may arise of whether to choose hysterectomy in order to exclude malignancy rather than a conservative treatment. (See "Elective oophorectomy or ovarian conservation at the time of hysterectomy".)
As with women with asymptomatic presumed leiomyomas, for most women with a symptomatic uterine mass, we recommend not choosing hysterectomy rather than other treatments based solely upon the goal of excluding malignancy. Reasonable exceptions to this are women with endometrial sampling and/or MRI results that strongly suggest sarcoma, thoracic imaging consistent with lung metastases, or multiple risk factors for uterine sarcoma.
On the other hand, for women deciding between several options for treatment of symptomatic fibroids, excluding malignancy may be a potential benefit of hysterectomy. As noted above, uterine sarcoma is rare but the prevalence is greater in symptomatic than asymptomatic women. Nonetheless, the risk of a complication of hysterectomy exceeds the risk of finding an undiagnosed malignancy . In addition, women who fail to respond to conservative therapy may have an increased risk of sarcoma and also may require definitive treatment. Thus, excluding malignancy may be one factor that influences the decision regarding whether to choose treatment with hysterectomy. (See 'Risk factors' above and 'Failure to respond to treatment' above and 'Choice of imaging modality' above and 'Endometrial sampling' above.)
Should unplanned hysterectomy be performed based on intraoperative findings? — During myomectomy or other pelvic surgery, a surgeon may encounter findings suggestive of a uterine sarcoma. Intraoperative findings rarely indicate the need for an unplanned hysterectomy, and sending pathology samples for evaluation and planning a potential second surgery pending the results is usually prudent. Gross characteristics of a tumor may be suggestive of sarcoma, but are not diagnostic. Frozen section analysis is often inconclusive. (See 'Intraoperative evaluation' above.)
The only indications for hysterectomy are a definitive frozen section diagnosis of sarcoma and/or gross evidence of metastatic disease. One note of caution is that women with apparent intraabdominal metastases may have a primary malignancy at another site or leiomyomatosis peritonealis disseminata, which is a rare and benign condition. Unplanned hysterectomy should not be performed in women of reproductive age without a pathologic diagnosis of sarcoma. Additionally, because oophorectomy has not been shown to influence prognosis for leiomyosarcomas, ovarian preservation may be carried out in the case of unexpected intraoperative findings of sarcoma . (See "Variants of uterine leiomyomas (fibroids)", section on 'Leiomyomatosis peritonealis disseminata'.)
Staging for an incidentally discovered intraabdominal malignancy is best performed by a surgeon experienced in these procedures. (See "Abdominal hysterectomy", section on 'Malignancy'.)
Do leiomyomas progress to sarcoma? — In general, it appears that uterine sarcomas do not arise from benign leiomyomas, with rare exceptions. Genetic evidence has been inconsistent over the years regarding whether sarcomas arise de novo or whether there is karyotypic evolution from leiomyomas to sarcomas, so called sarcomatous degeneration. The consensus from genetic studies has been that most sarcomas arise independently . Sarcomas typically have complex karyotypes and aneuploidy, while leiomyomas have characteristic rearrangements, many of which are shared by other benign tumors . Intermediate forms between these two patterns had not been described.
Histologic studies have found rare examples that appear consistent with progression from a leiomyoma to sarcoma . The most compelling evidence comes from a rare subgroup of leiomyomas with cellular or atypical histology, based upon data from two clinical and two molecular genetic studies [90-93]. In a clinical study, 3 of 18 women with cellular or atypical variants died of their disease . There was a longer latency between diagnosis and death in these patients compared with those with leiomyosarcoma (>6 years versus median of 2.1 years). There are no data regarding how often cellular or atypical histology are associated with such abnormal clinical behavior. (See "Variants of uterine leiomyomas (fibroids)", section on 'Benign histologic variants of leiomyomas'.)
SUMMARY AND RECOMMENDATIONS
●Benign uterine leiomyomas (fibroids) are the most common pelvic tumor in women (lifetime risk 70 to 80 percent). Uterine sarcoma is rare (3 to 7 per 100,000 in the United States population). The likelihood of finding a sarcoma in a population of women with an intrauterine mass, some of whom have risk factors for uterine sarcomas, is approximately 0.1 to 0.28 percent. (See 'Introduction' above and 'Prevalence of sarcoma after surgery for presumed leiomyomas' above.)
●Clinical manifestations are not useful to distinguish between leiomyomas and uterine sarcomas, since both typically present with abnormal uterine bleeding, pelvic pain/pressure, and a pelvic mass. (See 'Clinical manifestations' above.)
●A rapidly enlarging uterine mass is not a reliable sign of a uterine sarcoma in women of reproductive age. After menopause, on the other hand, a new or growing uterine mass warrants further evaluation. Postmenopausal hormone therapy may cause an increase in the size of an existing leiomyoma. (See 'Rapidly growing uterine mass' above and 'Increasing age and postmenopausal status' above.)
●Large uterine size (in excess of 20 gestational weeks) has not been shown to be associated with increased uterine sarcoma risk. (See 'Large or solitary uterine mass' above.)
●Endometrial sampling may detect uterine sarcoma in some patients. We suggest endometrial sampling for women who have a uterine mass and who have risk factors for uterine sarcoma and/or other findings that raise suspicion of uterine sarcoma. (See 'Endometrial sampling' above.)
●There is no pelvic imaging modality that can reliably differentiate between benign leiomyomas and uterine sarcomas. We suggest that women with a pelvic mass that is newly diagnosed or has changed markedly in size or mobility undergo a pelvic ultrasound as an initial imaging study rather than no imaging or imaging with another modality. (See 'Imaging' above.)
●Magnetic resonance imaging (MRI) may be helpful in women in whom there is a suspicion of sarcoma; however, it does not provide a definitive diagnosis. For women in whom uterine sarcoma is suspected based upon characteristics of the patient or mass or upon ultrasound findings, we suggest follow-up imaging with MRI rather than imaging with ultrasound alone or with other modalities. (See 'Imaging' above.)
●Counseling of women with presumed uterine fibroids includes discussion of all available treatment options and appropriate assessment for endometrial carcinoma and uterine sarcoma, including evaluation for current disease and risk factors. For women with a uterine mass who are undergoing laparoscopic hysterectomy or myomectomy and who have risk factors for uterine sarcoma (eg, postmenopausal status, history of ≥2 years of tamoxifen therapy, history of pelvic irradiation, history of childhood retinoblastoma, or personal history of hereditary leiomyomatosis and renal cell carcinoma [HLRCC] syndrome), we suggest NOT using power morcellation of uterine tissue with the potential for intraperitoneal dissemination (Grade 2C). Power morcellation is contraindicated in women with known or suspected uterine or other gynecologic cancer. (See 'Do morcellation, myomectomy, or supracervical hysterectomy worsen prognosis?' above.)
●If a surgical option using power morcellation is elected, counselling should include the risk of dissemination of malignant cells, if a malignancy is incidentally detected. (See 'Do morcellation, myomectomy, or supracervical hysterectomy worsen prognosis?' above and 'Professional society and FDA statements' above.)
●For most women with presumed uterine leiomyomas, whether asymptomatic or symptomatic, we recommend not performing hysterectomy for the sole purpose of excluding malignancy (Grade 1B). Reasonable exceptions to this are women with endometrial sampling and/or MRI results that strongly suggest sarcoma, those with thoracic imaging consistent with lung metastases, or those with multiple risk factors for uterine sarcoma. (See 'Asymptomatic women' above and 'Symptomatic women' above.)
●Leiomyomas do not appear to progress to sarcoma, with the exception of rare atypical or cellular variants. (See 'Do leiomyomas progress to sarcoma?' above.)
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