Uterine fibroids are one of the most common benign tumors in women’s reproductive system, with an overall prevalence of 11.21% in Chinese women in 2011. Traditional surgical treatment of uterine fibroids is mainly based on transabdominal myomectomy and total hysterectomy. With the development of technology, laparoscopic myomectomy, subtotal or total hysterectomy is now widely performed clinically. Meanwhile, vascular embolization (UAE) and high-intensity focused ultrasound (HIFU) have emerged and achieved better treatment results without surgery. The application and development of new technologies bring blessings to patients but also bring new challenges and risks to clinicians. How to properly face the risk of tumor dissemination brought by laparoscopic myomectomy spinocutaneous comminution, staging changes after sarcoma spinocutaneous comminution and dissemination, and the risk of not getting histopathological diagnosis with UAE and HIFU treatment are especially important for the application of new technologies in uterine fibroids. 1, the occurrence of uterine sarcoma and myxosarcoma sarcomatous transformation Uterine sarcoma (uterine sarcoma) is a general term for malignant tumors of mesenchymal tissue origin of the uterus. It mainly originates from uterine smooth muscle, endometrial mesenchyme, and uterine epithelial and non-epithelial tissues. It occurs overwhelmingly after the age of 40 years, especially in postmenopausal women, and rarely in younger women. The latest World Health Organization (WHO) guidelines on the staging of uterine sarcomas state that uterine sarcomas are divided into five main categories: uterine smooth muscle sarcoma, endometrial mesenchymal sarcoma, undifferentiated endometrial sarcoma, carcinosarcoma, and other rare sarcomas such as liposarcoma. Types such as uterine smooth muscle sarcoma, undifferentiated endometrial sarcoma, and carcinosarcoma have high malignancy, high recurrence rate, low five-year survival rate, and poor prognosis. A recent U.S. Food and Drug Administration (FDA) Meta-analysis reported that the ratio of uterine sarcoma to patients with uterine fibroids was 0.28%, while other studies reported an annual incidence of 0.64/100,000 for uterine sarcoma, with some sarcomas derived from malignant changes of uterine fibroids and difficult to distinguish from fibroids. Sarcoma of the uterus occurs mostly in women after 40 years of age, especially in postmenopausal women. Uterine smooth muscle sarcoma is the most common type of malignant transformation. Uterine sarcoma is mainly transmitted through blood and lymph, and the five-year survival rate is 17% to 55%. The five-year survival rate of patients with uterine smooth muscle sarcoma is closely related to the number of nuclear divisions/10HP (high-powered field of view), which is about 98% for 1-4 nuclear divisions/10HP; about 42% for 5-9 nuclear divisions/10HP; and about 15% for ≥10 nuclear divisions/10HP. Although uterine smooth muscle sarcoma is an extremely malignant tumor, those who develop sarcomatous transformation due to leiomyoma have a relatively good prognosis. There is still controversy regarding the origin of the malignant cells of uterine leiomyosarcoma. Some studies suggest that the malignant sarcoma cells are de novo growths, unrelated to the original myoma. It has been observed that there is a zone of transition from benign to malignant within the tissue of malignant uterine fibroids. 2. Differentiation of uterine leiomyoma from uterine sarcoma How to deal with the risk of tumor dissemination associated with laparoscopic rotary comminution and the inability to obtain a histopathological diagnosis with UAE and HIFU treatment. Early differential diagnosis of uterine leiomyoma and uterine sarcoma appears to be very important. Early detection of patients with suspected uterine sarcoma, avoidance of rotary comminution, UAE and HIFU treatment, and reduction of risks associated with surgical and clinical management are the keys that clinicians need to deal with. Uterine sarcomas tend to occur during perimenopause and postmenopause, and the median age of patients with uterine sarcoma is 52-57 years, while endometrial mesenchymal sarcoma is 50-52 years. Fibroids do not grow during perimenopause and postmenopause. If the fibroids increase in size during perimenopause and postmenopause without estrogen use, the possibility of sarcoma needs to be suspected. More than half of the patients with uterine sarcoma are seen primarily for postmenopausal vaginal bleeding or irregular vaginal bleeding, and another 13% to 35% are seen for pain. Postmenopausal vaginal bleeding requires preoperative diagnostic curettage and can reveal 30% of sarcomas and 70% of endometrial mesenchymal sarcomas. Diagnostic curettage is necessary for uterine sarcoma combined with irregular vaginal bleeding. Of the 938 pathological specimens with total hysterectomy for malignancy, 72 of the 142 pathological tissues considered for sarcoma had preoperative endometrial pathology, 62 of which had sarcoma on endoscopic diagnostic pathology. In this study, preoperative irregular vaginal bleeding was not registered and analyzed to clarify which patients underwent diagnostic scraping; therefore, diagnostic scraping of the endometrium plays an important role in the diagnosis of patients with uterine sarcoma with symptoms of irregular vaginal bleeding. The role of imaging-guided puncture biopsy remains incompletely understood, and the predictive value of puncture biopsy is currently considered low, mainly because of the presence of large areas of necrotic sarcoma tissue and the inability of puncture tissue to provide a definitive pathologic diagnosis. Currently, there is a lack of specific tumor markers for uterine sarcoma, and there is still a lack of research on the possible correlation between lactate dehydrogenase (LDH) and CA125 and the development of uterine sarcoma. In a prospective study, 227 patients with uterine fibroids and 10 patients with uterine sarcoma in the observation group had statistically significant differences in elevated LDH and LDH-3. Studies have reported that CA125 is elevated in patients with uterine sarcoma, especially advanced uterine sarcoma. In 42 patients with uterine sarcoma, preoperative CA125 was significantly higher than in the uterine smooth muscle tumor group, but there was no significant difference in CA125 in the comparison of early uterine sarcoma and uterine smooth muscle tumor, which limits the use of CA125 in the early diagnosis of uterine sarcoma. There are no specific diagnostic indicators for uterine sarcoma in imaging, and Doppler color ultrasound plays an important role in differentiating uterine fibroids from sarcomas, although this finding remains controversial. Uterine sarcomas are largely altered by necrosis and hemorrhage, and rapidly growing sarcoma cells require abundant vascularity for nutritional support, whereas in uterine smooth muscle tumors, the vasculature is mostly within the pseudo-envelope of the fibroids in an encapsulated blood flow. In a study comparing 8 cases of uterine sarcoma and 3 cases of smooth muscle tumor of undetermined malignant potential with 225 cases of uterine leiomyoma by ultrasound, the uterine sarcoma was significantly larger in size than smooth muscle tumor and all were solitary, 7 of 8 cases were >8 cm in diameter, degenerative necrosis was seen in 4 sarcomas, and abundant blood supply was seen in the center and around the tumor in 7 cases; the sensitivity rate, specificity rate, and correctness rate of abundant blood supply in the center and around the tumor in diagnosing uterine sarcoma were 100% and 86%, respectively. The correct rates were 100%, 86%, and 19%, respectively. Combining with other ultrasound indices, the correct rate could be increased to 60%, but the sensitivity rate decreased to 75%. Doppler ultrasound of uterine sarcoma can show a lower systolic peak with a sensitivity of 80% and specificity of 97%. There is still a lack of studies related to 3D ultrasound in the differentiation of uterine fibroids from sarcomas. According to ultrasound imaging features, a single, oval, rich blood supply, irregularly diverse myometrial tumor >8 cm in diameter with central necrosis and cystic changes and no central calcification is a condition that requires a high degree of suspicion for uterine sarcoma. Magnetic resonance imaging (MRI) images are superior to CT imaging and can provide a good picture of the level of the myoma and the relationship of the adjacent organs in the pelvis, and clarify the extent of tumor tissue invasion. mri T2-weighted imaging can well help determine the extent of tumor invasion within the uterus, and also distinguish between uterine fibroids and uterine sarcomas. mri uterine sarcomas are T1 inhomogeneous low signal and T2 high signal on mri, while smooth muscle tumors Most of them show T2 low signal. Magnetic resonance diffusion-weighted imaging (DWI) imaging can better differentiate between leiomyosarcoma and sarcoma. Uterine sarcomas exhibit high signal on DWI, and the average apparent diffusion coefficient (ADC) values of uterine sarcomas are lower than those of normal myometrium, and there is no overlap between the two. Uterine sarcoma exhibiting high signal on DWI and reduced ADC values may be related to the high cell density of the tumor and the increased nucleoplasmic ratio limiting the free diffusion of water molecules. Based on the above principles, it is difficult to differentiate uterine sarcoma from cell-rich uterine leiomyoma based on DWI signal and ADC value measurements alone CT can evaluate liver metastases and lung metastases in advanced sarcoma, but has no role in differentiating early sarcoma from leiomyoma. However, positron emission computed tomography (PET-CT) plays a very crucial role in the diagnosis of uterine sarcoma and is expected to be the most valuable test in preoperative examination. However, PET-CT is too expensive and difficult to perform routinely for all laparoscopic total hysterectomy preoperative examinations. In PET-CT for the diagnosis of uterine sarcoma, 18 fluoro-deoxyglucose (FDG) is the most commonly used contrast agent, and usually, the main causes of elevated metabolic values of FDG are estrogenic status, surplus cells, and malignancy. In a retrospective study comparing different imaging diagnostic methods for uterine sarcoma, all five cases of uterine sarcoma were considered as sarcoma by PET-CT, of which four cases were confirmed by MRI and two by Doppler ultrasonography, with PET-CT having higher diagnostic accuracy. The accuracy of another contrast agent, FES, compared with FDG, increased from 81% to 93% for the diagnosis of uterine sarcoma. 3. Prevention of laparoscopic spinotomy dissemination Some scholars first introduced the laparoscopic spinotomy device into laparoscopic abdominal surgery in 1993, and the U.S. Food and Drug Administration (FDA) officially approved the use of spinotomy in laparoscopy in 1995, and the laparoscopic spinotomy device has been greatly promoted since then. However, on 2014-04-17 the FDA issued a safety warning “Laparoscopic Comminution in Hysterectomy and Myomectomy”. The use of laparoscopic comminution in hysterectomy or myomectomy in the treatment of fibroids is discouraged. This is because there is no reliable method to predict whether a myoma is a uterine sarcoma or not. Clinicians are also advised to thoroughly discuss the benefits and risks of treatment for all patients and to inform patients that laparoscopic comminution may result in the spread of myomas containing unexpected cancerous tissue, worsening the prognosis significantly. A greater number of gynecologists have offered differing views on this warning, with the vast majority of experts believing that the advantages gained by choosing laparoscopic surgery for patients with uterine fibroids outweigh the risks associated with myoma comminution. Fifty-six cases of uterine smooth muscle sarcoma were analyzed from 1989-2010, 25 of which underwent myoma crushing and 31 transabdominal surgery. The study confirmed that myoma comminution increased the risk of pelvic and abdominal metastases from sarcoma, while significantly decreasing patient disease-free survival and overall survival. Stage I sarcoma tissue was staged up to stage III after spinotomy, and its 5-year survival rate dropped from 51% to 0. However, members of the American Association for Gynecologic Laparoscopy (AAGL) published an updated article claiming that the FDA’s warning was biased. The risk of truly unknown sarcoma would be very low, and a model was presented confirming that the risk of morbidity and mortality from propagation of the underlying tumor by rotary comminution of smooth muscle sarcoma (LMS) is lower than that of total hysterectomy. In China, a patented technique of laparoscopic-assisted spinotomy of uterine fibroid specimen bag was proposed before the FDA warning, in which the tumor tissue specimen is implanted in a relatively airtight protective bag and crushed and removed under laparoscopic monitoring to avoid medical dissemination of malignant tumor. Following the FDA warning, Cohen et al. in the United States have filed a patent in the United States for the use of a rotational pouch to avoid dissemination of the tumor during laparoscopic myomectomy. Placement of the tumor in a bag for spinotomy theoretically prevents dissemination of the shredded tumor, but the safety and efficacy of these spinotomy bags has not been demonstrated. This technology is still in its infancy and there is no doubt that rotating the leiomyosarcoma within the pouch is relatively safe and avoids many of the potential complications of comminution, such as direct rotational injury, dissemination of the leiomyosarcoma, and sarcoma staging changes. However, not all risks are addressed, such as the tendency of the laparoscopic body to puncture the pouch for better visualization of the anterior end of the rotator during laparoscopic surgery, leading to exenteration of the tumor.Cohen et al. performed an ex vivo trial of rototomy using a bovine tongue specimen, which was rototomized in an ex vivo specimen pouch, and only 1 of 13 cases experienced rupture of the rototomy pouch. After spinotomy of the tumor using the spinotomy bag, the bag was removed and the pelvic cavity was repeatedly flushed, and no smooth muscle cells were seen in the centrifugal flush. With the development of the study, some scholars have proposed transvaginal pouch in spinotomy of myoma, but its indications still need to be studied and the role of spinotomy in transvaginal pouch needs to be further evaluated. 4, Conclusion For laparoscopic myoma spinotomy, it is still recommended that hospitals with the condition to choose spinotomy specimen in the bag for spinotomy operation to avoid dissemination of the tumor. Preoperative assessment of abnormally rich blood supply, postmenopausal bleeding and myomas that continue to grow after menopause, and myomas with predominantly painful symptoms should be avoided for laparoscopic crushing. For patients with fibroids combined with irregular vaginal bleeding and other high-risk factors, necessary pelvic MRI, diagnostic curettage and other adjuncts are very important to detect a portion of sarcomas and most endometrial cancers. If the possibility of sarcoma transformation is highly suspected, transabdominal surgery or total hysterectomy are better options.