Uterine fibroid is the most common benign tumor of the female. The prevalence of uterine fibroids in women aged less than 50 years is estimated at 70% [6]. Uterine sarcoma is rare and the UUS was only a part of uterine sarcoma. In this study, the incidence of unexpected uterine sarcoma was 0.67%, which is slightly higher than that previously reported (0.09–0.49%). This discrepancy may be attributable to insufficiently large sample size or a lack of symptoms that would have alerted the attending physician to the correct diagnosis preoperatively. The difference in the incidence of unexpected uterine sarcoma between patients undergoing laparoscopic surgery and those undergoing transabdominal surgery was not statistically significant. However, the incidence of unexpected uterine sarcoma was higher in patients undergoing total hysterectomy than in those undergoing tumor resection, because UUS patients’ average age of onset is greater than 45 years, so were advised to undergo a total hysterectomy.
Common clinical manifestations of uterine sarcoma include irregular vaginal bleeding, lower abdominal mass, abnormal vaginal discharge, and compression symptoms. Because it is difficult to distinguish between these symptoms and those of uterine fibroids, the vast majority of patients with uterine sarcomas are preoperatively misdiagnosed as having uterine fibroids. Zhang [5] et al. reported a statistically significant difference in the incidence of compression symptoms between patients preoperatively diagnosed as having uterine sarcoma and those with unexpected uterine sarcoma (P = 0.018), maybe because patients with compression symptoms were eager to gain relief of uncomfortable symptoms through surgery and their preoperative evaluation was inadequate.
The advantages of laparoscopic surgery include reducing blood loss, time to wound healing, the incidence of wound infections, and duration of hospital stay, and enabling a quick recovery and return to daily activities. Because of these benefits, a growing number of patients, especially those with a single uterine fibroid or planning to undergo a total hysterectomy, prefer to undergo laparoscopic surgery. The literature suggested that the percentage of patients with uterine fibroids undergoing laparoscopic surgery reportedly increased from 11% in 2003 to 29% in 2013 [7]. Morcellators were first used in gynecological surgery in 1993 and were formally approved by the FDA for gynecological laparoscopic surgery in 1995; their use has been greatly promoted since then [8]. On 17 April 2014, the FDA issued a safety statement regarding the use of laparoscopic morcellator in uterine fibroid surgery [9]. The resected uterus should be removed per vagina or via an abdominal incision and resected fibroids should be removed after being crushed in a sealed specimen bag. Unexpected pathological diagnosis of uterine sarcoma after morcellation should be recorded and the patient closely followed up. However, the use of laparoscopic morcellation has also increased the risk of the spread of unexpected malignancies, especially uterine sarcoma. In recent years, some scholars have reported that patients with unexpected uterine sarcomas may have adverse surgical outcomes that are attributable to an increased risk of spread of malignancy associated with the use of electric uterine/fibroid morcellators during laparoscopic surgery. The risk of tumor is higher when an electric morcellator is used than in other laparoscopic procedures; however, the precise relative risk is not known [10]. It has been reported that progression of disease was sped up in about 30% of the 53 unexpectedly discovered sarcomas discovered in 17,903 women undergoing surgery for fibroids and that 1/1000 morcellations will contribute to a poor prognosis [11]. Hinchcliff [12] et al. have shown that the use of a morcellator increases the risk of abdominal/pelvic recurrence of patients (P = 0.001) and shortens the median tumor-free survival time (10.8 vs. 39.6 months; P = 0.002) but does not affect the overall survival. Yang [13] reported multiple pelvic recurrences in one patient 240 days after using a morcellator and considered that the use of the morcellator may have been in part responsible for the recurrences. Hur [14] et al. have shown that 0.28% of patients with uterine fibroids who have undergone total hysterectomy have unexpected uterine sarcoma and that in these patients, performing morcellation during laparoscopic total hysterectomy reduces the five-year overall survival rate by 27% and shortens the recurrence-free survival time by 28.8 months. Two of the 28 patients with unexpected uterine sarcoma followed up in the present study had recurrences; one of them underwent LTH and the other transabdominal total hysterectomy. Six of the 45 patients underwent laparoscopic surgery, four patients LTH, and two laparoscopic tumor resections; a morcellator was used in two of the patients who underwent laparoscopic tumor resection. No tumor spread or recurrence was found during the second surgery two weeks later or during follow-up. However, one patient who underwent a total hysterectomy had a recurrence 11 months after surgery. In this study, the use of laparoscopic morcellation did not increase the recurrence rate because we used the in-bag morcellation method. However, further larger studies with longer follow-up are needed.
Patients with uterine fibroids generally have a long history with many outpatient checks, so changes in their fibroids should be documented in records and ultrasound reports rapid growth of uterine fibroids or continued growth after menopause should attract attention. Patients with irregular vaginal bleeding and abdominal pain preoperative diagnostic curettage or hysteroscopy should be performed. Patients suspected of having fibroid degeneration or with ultrasound indications of irregular or unclear blood flow should undergo pelvic nuclear magnetic resonance examination and those in whom a definite diagnosis is not established should undergo laparotomy.
The rapid frozen-section pathological examination should be performed intraoperatively on brittle masses or masses with indistinct boundaries: this is the last opportunity to diagnose an unexpected uterine sarcoma in time to perform an appropriate procedure and thus avoid a subsequent second surgical procedure. In the study, 14 patients underwent rapid frozen-section examination and 11 of those patients underwent the total hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy based on the results of the frozen-section examination, thus obviating the need for a second surgical procedure or laparoscopic surgery.