Objective
The purpose of this study was to describe the incidence and risk factors for uterine sarcomas and parasitic myomas at the time of power morcellation.
Study Design
We performed a retrospective review of 3523 women who underwent laparoscopic hysterectomy from 2001-2012. Univariate analyses were used for the morcellation cases to identify potential risk factors. Multivariable logistic regression was performed.
Results
Nine hundred forty-one patients underwent power morcellation at the time of hysterectomy; 10 of 941 patients (1.1%) were diagnosed subsequently with uterine sarcomas or parasitic myomas. The overall incidence of uterine sarcoma was 6 of 941 (0.6%), with a median age of 47 years (range, 41–52 years). There was no association among any of the factors analyzed and uterine sarcoma. Three of 6 patients had sarcoma diagnosed on initial pathologic evaluation of the morcellated specimen; 3 patients had delayed diagnosis of sarcoma with benign disease at the time of the initial procedure (median time to second evaluation, 6 years). For parasitic myomas (n = 4), the median age was 35 years (range, 32–40 years), and the median time to second evaluation was 5 years. On multivariate analysis, age <40 years (odds ratio, 26; 95% confidence interval, 2.7015–261.9; P ≤ .01) was associated with higher risk of the development of parasitic myomas.
Conclusion
Uterine sarcoma was found in 0.6% of patients who underwent power morcellation but was not found to be associated significantly with any preoperative factors. All 6 cases were noted to have apparent fibroid tumors as an indication for their hysterectomy. Age <40 years was a risk factor for parasitic myomas after power morcellation. Patients should be counseled about these complications before power morcellation.
See related editorial, page 553
More than 600,000 hysterectomies are performed in the United States annually, with 40% performed laparoscopically. Laparoscopic hysterectomy is associated with fewer postoperative complications, less blood loss, less postoperative pain, decreased hospital stay, and faster recovery time when compared with the open abdominal approach. Power morcellation is performed during laparoscopic supracervical hysterectomy, laparoscopic myomectomy, and laparoscopic total hysterectomy when the uterus is too large to pass through the vaginal canal. It involves the division of uterine tissue with the use of a rotating circular blade to facilitate removal of the specimen. Power morcellation has raised concern for potential dissemination of benign or malignant tissue. The Food and Drug Administration (FDA) recently issued a warning discouraging the use of power morcellation with uterine fibroid tumors.
Spindle cell neoplasms are tumors of the uterine smooth muscle or endometrial stroma. They include parasitic myomas and uterine sarcomas. Uterine sarcomas are malignant tumors of uterine connective tissue and include leiomyosarcoma, endometrial stromal sarcoma, carcinosarcoma, and undifferentiated sarcoma, with a reported incidence of 0.2%. They often behave more aggressively and are associated with a poorer prognosis than endometrial cancers. There are no specific symptoms or signs or reliable diagnostic modalities to differentiate benign from malignant uterine tumors before they are morcellated and removed. Parasitic myomas are defined as leiomyomas that are not attached to the uterus and are “parasitic” because they receive their blood supply from surrounding organs. They have a reported incidence of 0.12-0.9% after laparoscopic surgery with power morcellation.
The objectives of this study were (1) to describe the rates of spindle cell neoplasm formation after power morcellation and (2) to identify risk factors for formation of either uterine sarcoma or parasitic myomas at the time of laparoscopic hysterectomy with power morcellation.
Materials and Methods
This was an institutional review board–approved, retrospective study of women who underwent laparoscopic hysterectomy at Kaiser Permanente San Diego from 2001-2012.
Patient charts were reviewed after cases were identified with the use of surgical case logs. Demographic and clinical characteristics, surgical techniques, pathology reports, and perioperative complications were abstracted by physician reviewers and individually entered into an Access Database (Microsoft Access 2007; Microsoft Inc, Seattle, WA). Baseline characteristics were collected: age, gravidity, parity, ethnicity, body mass index, presence of diabetes mellitus, hypertension, collagen vascular disease, use of tobacco, alcohol, or drugs, presence of sexual activity, menopausal status, use of hormones, use of leuprolide or the progestin intrauterine device, number of vaginal deliveries, and history of pelvic surgery or endometrial ablation. Pathology reports were carefully reviewed and coded for the presence of fibroid tumors, endometriosis, adenomyosis, endometrial hyperplasia, cervical dysplasia, or malignancy. Operative techniques, removal of the ovaries, uterine specimen weight, estimated blood loss, and complications were also abstracted.
Total laparoscopic hysterectomy was defined as removal of the uterus and cervix. If the uterine body was too large to fit through the vagina, it was often morcellated laparoscopically to facilitate retrieval. Laparoscopic supracervical hysterectomy was defined as removal of the uterus above the level of the cervix followed by laparoscopic morcellation to remove the uterine body. In this study, bags were not used to contain morcellated contents.
To address our primary objective, we evaluated patients who underwent power morcellation and identified those diagnosed with either uterine sarcoma or parasitic myomas. Fisher exact test and Mann Whitney U test were used to conduct univariate analyses to identify potential risk factors for parasitic myomas and for uterine sarcoma. The 28 baseline characteristics listed previously were analyzed as potential risk factors. Multivariable logistic regression was used to assess the independent risk factors. Variables were included if they had a probability value of < .10 on univariate analysis or if the variable was determined to be an important biologic risk factor. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. A probability value of < .05 was considered statistically significant. Statistical analysis was performed with SPSS software (version 18.0, SPSS Inc, Chicago, IL).
Results
A total of 3523 women underwent laparoscopic hysterectomy. Of these, 941 women underwent power morcellation. Of those who had power morcellation, 10 women were subsequently diagnosed with uterine sarcoma or parasitic myomas, for an overall incidence of 1.1% (10/941 women).
Uterine sarcoma
Of the 10 women who received a diagnosis of spindle cell neoplasms, 6 tumors (0.6%) were uterine sarcomas. Demographic characteristics are shown in Table 1 . Three of the 6 uterine sarcomas were endometrial stromal sarcomas, and 3 were leiomyosarcomas (2 low-grade and 1 high-grade; Table 2 ). Only 3 of the 6 patients received a diagnosis of uterine sarcoma on pathologic evaluation at the time of hysterectomy with morcellation. These 3 patients underwent subsequent exploratory laparotomy, trachelectomy, and bilateral salpingo-oophorectomy (if not performed at time of hysterectomy). One patient required resection of metastatic implants, omentectomy, appendectomy, and adjuvant therapy with the use of Megace ( Table 3 ; patients #1-3). The other 3 patients were examined from 2-7 years after hysterectomy with ≥1 pelvic masses; pathologic evaluation of these recurrent masses revealed uterine sarcoma (patients #4-6). There were no significant associations among any of the potential risk factors and uterine sarcoma.
| Variable | Uterine sarcoma | P value | |
|---|---|---|---|
| No (n = 935) | Yes (n = 6) | ||
| Mean age, y a | 46 ± 6 | 44 ± 5 | .65 b |
| Body mass index, kg/m 2 a | 29 ± 6 | 30 ± 12 | .73 b |
| <25 kg/m 2 , n (%) | 222 (26) | 3 (50) | .18 c |
| ≥25 kg/m 2 , n (%) | 642 (74) | 3 (50) | |
| Ethnicity, n (%) | .61 c | ||
| White | 530 (57) | 4 (67) | |
| Hispanic | 200 (21) | 2 (33) | |
| African American | 129 (14) | 0 | |
| Asian/other/unknown | 76 (8) | 0 | |
| Smoking (current), n (%) | 95 (11) | 0 | .40 c |
| Diabetes mellitus, n (%) | 49 (5) | 0 | .56 c |
| Hypertension, n (%) | 224 (24) | 1 (17) | .67 c |
| Menopausal, n (%) | 73 (8) | 1 (17) | .43 c |
| Hormones (at time of history and physical), n (%) | 215 (26) | 2 (33) | .23 c |
| Use of leuprolide, n (%) | 327 (39) | 2 (33) | .66 c |
| Use of progestin intrauterine device, n (%) | 18 (2) | 0 | .76 c |
| Type of laparoscopic hysterectomy performed, n (%) | .54 c | ||
| Total laparoscopic hysterectomy | 262 (28) | 1 (17) | |
| Supracervical laparoscopic hysterectomy | 673 (72) | 5 (83) | |
| One or both ovaries left intact, n (%) | 608 (65) | 3 (50) | .37 c |
| Uterine weight, g a | 333 ± 261 | 458 ± 248 | .25 b |
| >350 g, n (%) | 262 (28) | 3 (50) | .36 c |
| Fibroid tumors (pathologic specimen), n (%) | 802 (86) | 5 (83) d | .87 c |
| Adenomyosis (pathologic specimen), n (%) | 240 (26) | 1 (17) | .61 c |
| Endometriosis (pathologic specimen), n (%) | 64 (7) | 0 | .51 c |
a Data are given as mean ± standard deviation
d All 6 patients who were diagnosed with uterine sarcoma had apparent fibroid tumors before surgery. Five patients had fibroid tumors noted on pathologic specimen from initial surgery (represented in this variable); 1 patient had only sarcoma without mention of fibroid tumors on specimen.
| Patient | Age, y | Menopausal at time of hysterectomy | Indication for hysterectomy | Preoperative endometrial biopsy | Preoperative ultrasound scan | Procedure | Uterine weight, g | Disease at initial procedure |
|---|---|---|---|---|---|---|---|---|
| 1 | 47 | No | Fibroid tumors, menorrhagia | Benign | Enlarged uterus (20 × 10 × 9 cm), fundal fibroid tumor (8 × 9 × 10 cm) | Laparoscopic supracervical hysterectomy, bilateral salpingo-oophorectomy | 720 | Low-grade endometrial stromal sarcoma |
| 2 | 41 | No | Fibroid tumors, menorrhagia | Benign | Fibroid uterus, abnormal heterogeneity of the endometrium | Laparoscopic supracervical hysterectomy | 218 | Low-grade endometrial stromal sarcoma |
| 3 | 51 | Yes | Fibroid tumors, postmenopausal bleeding | None: frozen section curettage done at time of procedure (benign) | Enlarged uterus (14 × 5 × 7 cm), 2 fibroid tumors (3 × 4 × 4 cm) and (5 × 5 × 4 cm) | Laparoscopic supracervical hysterectomy, bilateral salpingo-oophorectomy | 285 | Leiomyosarcoma, grade II-III |
| 4 | 45 | No | Fibroid tumors, menorrhagia, abdominal discomfort | Benign | None | Total laparoscopic hysterectomy with uterine morcellation, left salpingo-oophorectomy | 787 | Cellular leiomyoma, usual type leiomyoma (review of disease: endometrial stromal sarcoma) |
| 5 | 41 | No | Fibroid tumors, pelvic pan | None | None | Laparoscopic supracervical hysterectomy | 486 | Pieces of leiomyoma |
| 6 | 48 | No | Fibroid tumors, menorrhagia | Benign | Slightly enlarged uterus (10 × 7 × 8 cm), 6 cm posterior fibroid tumor | Laparoscopic supracervical hysterectomy, bilateral salpingo-oophorectomy | 250 | Pieces of leiomyoma, adenomyosis |
| Patient | Sarcoma diagnosed at initial procedure | Time to second evaluation | Symptoms | Restaging | Tumor type | Adjuvant treatment | Follow up, mo | Survival status |
|---|---|---|---|---|---|---|---|---|
| 1 | Yes | N/A | N/A | Yes: exploratory laparotomy, trachelectomy, resection of metastatic implants, omentectomy, appendectomy | Low-grade endometrial stromal sarcoma | Megace | 135 | Alive; no disease |
| 2 | Yes | N/A | N/A | Yes: exploratory laparotomy, trachelectomy, bilateral salpingo-oophorectomy; no evidence of disease | Low-grade endometrial stromal sarcoma | None | 48 | Alive; no disease |
| 3 | Yes | N/A | N/A | Yes: exploratory laparotomy, trachelectomy; no evidence of disease | Leiomyosarcoma, grade II-III | None | 31 | Alive; no disease |
| 4 | No | 23 mo | Pelvic pain | Yes: exploratory laparotomy, bilateral salpingo-oophorectomy, resection of pelvic masses, omentectomy; bowel resection and anastomosis | Low-grade endometrial stromal sarcoma | Megace | 75 | Alive; no disease |
| 5 | No | 7 y | Pelvic pressure | Yes: exploratory laparotomy, resection of abdominopelvic mass, bilateral salpingo-oophorectomy | Low-grade leiomyosarcoma | None | 51 | Alive; no disease |
| 6 | No | 6 y | Abdominal pain | Yes: exploratory laparotomy, resection of pelvic masses, appendectomy | High-grade leiomyosarcoma | Chemotherapy, radiation, additional excision of recurrent masses | 36 | Died of disease |
Uterine sarcoma with initially benign pathologic evidence
Three of the women in the uterine sarcoma group had benign leiomyoma on initial pathologic evaluation and then had a delayed presentation of ≥1 abdominal or pelvic masses that subsequently were found to be uterine sarcoma. Incidence of this presentation was 0.3% (3/941 women). The median age of these patients at the time of initial procedure was 45 years, and the median uterine weight at the time of morcellation was 486 g. The median amount of time to second evaluation was 6 years. All patients were imaged with a computed tomography scan, which revealed single or multiple pelvic masses, the largest of which was 15 × 16 cm ( Figure 1 ). All patients underwent exploratory laparotomy and resection of masses. On final pathologic evaluation, 1 patient was diagnosed with endometrial stromal sarcoma, and 2 patients were diagnosed with leiomyosarcoma (1 low grade; 1 high grade.) Associated risk factors were not found to be significant.
Two of these 3 patients had their original pathologic specimens reviewed at the time of the second evaluation. It was determined on re-review that patient #4 who was originally reported to have a cellular leiomyoma on her morcellated specimen actually had a low-grade endometrial stromal sarcoma at the time of initial surgery. This report was officially amended. Patient #5 did not have an amended pathology report, and the tissue specimen was no longer available for review at the time of this study. It was unclear from the records whether that pathology report was reviewed officially and left unchanged or never reviewed. Patient #6 (high-grade leiomyosarcoma, 6 years after initial surgery) had her disease reviewed, and high-grade leiomyosarcoma was not found on the available tissue specimen of her original morcellated uterus.
At the time of the study conclusion, 5 of the 6 patients who had morcellation of uterine sarcoma were living without evidence of recurrent disease, with a minimum of 31 months of follow up. The patient with high-grade leiomyosarcoma had died of the disease 3 years after diagnosis (patient #6).
Uterine sarcoma in patients who did not undergo morcellation
Our primary objective was to describe the incidence of uterine sarcomas and parasitic myomas at the time of power morcellation. However, we thought it would be interesting to also report the incidence of sarcoma in the patients who did not undergo morcellation in our laparoscopic hysterectomy population. During the same study period, a total of 2582 women underwent laparoscopic hysterectomy but did not have power morcellation. All women underwent total hysterectomy at a mean age of 46 ± 8 years and uterine weight 189 ± 141 g. Of these, 5 women received a diagnosis of uterine sarcoma (0.19%; 5/2582 women). Two women received a diagnosis of low-grade endometrial stromal sarcoma, 1 with carcinosarcoma and 2 with leiomyosarcoma (1 high-grade, 1 grade not specified). In addition, 2 patients received a diagnosis of smooth muscle tumor of uncertain malignant potential. At the time of study conclusion, 4 of the 5 patients with a diagnosis of sarcoma and the 2 patients with smooth muscle tumor of uncertain malignant potential were alive without evidence of disease at a minimum of 37 months of follow up. The patient with high-grade leiomyosarcoma died of the disease 2 years after diagnosis. The details of the clinical courses of these patients can be found in Table 4 .
| Patient | Age | Menopausal at time of hysterectomy | Indication | Preoperative endometrial biopsy | Preoperative ultrasound scan | Procedure | Uterine weight, g | Tumor type | Adjuvant treatment | Follow up, mo | Survival |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 81 | Yes | Endometrial biopsy with adenosarcoma | Adenosarcoma | None | Total laparoscopic hysterectomy, bilateral salpingo-oophorectomy | 109 | Adenosarcoma | None | 37 | Alive; no disease |
| 2 | 49 | No | Fibroid tumors, pelvic pain | Benign | Enlarged uterus (15 × 4 × 7 cm), left posterior fibroid tumor (3 × 3 × 4 cm) | Total laparoscopic hysterectomy, right salpingo-oophorectomy | 154 | Low-grade endometrial stromal sarcoma | None | 65 | Alive; no disease |
| 3 | 49 | No | Enlarged uterus, abnormal uterine bleeding | Benign | Enlarged uterus (11 × 8 × 7 cm) | Total laparoscopic hysterectomy, bilateral salpingo-oophorectomy | Unknown | Low-grade endometrial stromal sarcoma | None | 40 | Alive; no disease |
| 4 | 66 | Yes | Postmenopausal bleeding | Benign (1 y previously) | Fundal fibroid tumor (7 × 7 × 7 cm) | Total laparoscopic hysterectomy, bilateral salpingo-oophorectomy | 383 | Leiomyosarcoma (grade not specified) | None | 37 | Alive; no disease |
| 5 | 54 | Yes | Fibroid uterus, postmenopausal bleeding | Benign | Enlarged uterus (14 × 8 × 8 cm), multiple fibroid tumors, largest 5.2 cm | Total laparoscopic hysterectomy, bilateral salpingo-oophorectomy | 268 | High-grade leiomyosarcoma | Multiple rounds and agents of chemotherapy | 23 | Died of disease |
| 6 | 44 | No | Fibroid tumors, ovarian mass, cervical dysplasia | Benign | Multiple fibroid tumors, largest (5 × 5 × 3 cm) | Total laparoscopic hysterectomy, bilateral salpingo-oophorectomy | 184 | Smooth muscle tumor of uncertain malignant potential | None | 52 | Alive; no disease |
| 7 | 33 | No | Smooth muscle tumor of uncertain malignant potential on endometrial biopsy | Leiomyoma vs stromal lesion, favor smooth muscle tumor of uncertain malignant potential | Lower uterine fibroid tumor (4 × 5 × 4 cm) | Laparoscopic assisted vaginal hysterectomy | 96 | Smooth muscle tumor of uncertain malignant potential | None | 46 | Alive; no disease |
Parasitic myomas
The remaining 4 of 10 women diagnosed with spindle cell neoplasms were found to have parasitic myomas (0.4%; 4/941 women). The demographic characteristics of these patients are shown in Table 5 . All women with parasitic myomas received the diagnosis many years after their laparoscopic hysterectomy; the median amount of time to evaluation was 5 years. The most common symptom was a self-palpated mass, followed by abdominal pain. One patient was asymptomatic, and the recurrent myomas were noted at the time of surgery for pelvic organ prolapse repair. All of the patients who had symptoms underwent computed tomography scanning, which showed single or multiple pelvic masses, the largest of which was 18 × 18 cm ( Figure 2 ). All patients underwent subsequent reoperation with resection of pelvic masses; 2 of the women had laparoscopy, and 2 women underwent exploratory laparotomy. Final pathologic evidence for all of these patients showed benign leiomyoma, and all patients were living without evidence of recurrence at the time of the study conclusion.
