Sarcoma of the uterus (sarcoma of uterus) is a group of malignant tumors originating from the smooth muscle tissue of the uterus, the interstitial tissue of the uterus, the intrauterine tissue or the extrauterine tissue. Sarcoma of uterus is a rare malignant tumor of female genital organs, accounting for 2-4% of malignant tumors of uterus and 1% of malignant tumors of genital tract. It is highly malignant and is mostly seen in pre- and post-menopausal women. This tumor originates from the mesoderm and can arise from the muscle, connective tissue, blood vessels, endometrial stroma, or myomas of the uterus. The histologic origin is usually from the myometrium, but can also be from the connective tissue within the myometrium or the connective tissue of the endometrium. The incidence of sarcoma is about 20-40%, mostly seen in women aged 30-50 years, and can be found in all parts of the uterus, with the uterine corpus far more common than the cervix at about 15:1. Uterine sarcoma accounts for 2-5% of malignant tumors of the uterus, with a predilection for age 50 years, while cervical chylomicron sarcoma is mostly seen in young girls. The preoperative diagnosis rate is only 30-39% because there are no specific symptoms in the early stage. Clinical staging Uterine sarcoma is generally staged according to the staging criteria of the International Association Against Cancer (UICC-AJCCS) for uterine sarcoma, but in recent years, some people also advocate staging endometrial mesenchymal sarcoma and malignant mullerian duct hybrid tumor with reference to the 1988 FIGO surgical pathological staging criteria for endometrial cancer. Clinical staging of uterine sarcoma according to UICC-AJCCS staging criteria: Stage I: cancer is limited to the uterine body Stage II: cancer has involved the cervical canal Stage III: cancer has gone beyond the uterus and invaded other organs and tissues of the pelvis, but still limited to the pelvis Stage IV: cancer has gone beyond the pelvis, invaded the epigastric cavity or has metastasized distantly Metastasis of uterine sarcoma: there are three main metastatic pathways of uterine sarcoma: 1. 1.Blood dissemination is the main route of metastasis, which can be transferred to the liver, lung and other parts of the body through blood circulation. 2.Direct infiltration of sarcoma can directly invade the myometrium and even reach the plasma layer of the uterus, causing intra-abdominal dissemination and ascites. 3.Lymph node metastasis, which is less common in the early stage and more common in the late stage with high malignancy. Etiology The clinical incidence of uterine sarcoma is low, and the cause of its development is unclear. It has been suggested histogenetically that it is related to embryonic cell remnants and mesenchymal cell metastasis, but there is no clear evidence to support this inference. Main clinical manifestations (1) Irregular vaginal bleeding with high volume. If the tumor is necrotic or forms ulcers, it may discharge pus and blood-like or rice-soup-like foul fluid. Vaginal discharge increases; it may be plasma, bloody or white, and may be purulent and foul-smelling when combined with infection; vaginal bleeding or abnormal menstruation after menopause. It accounts for 65.5%-78.2% (2) abdominal masses, which can sometimes be felt by oneself and can increase rapidly especially with uterine fibroids. If the sarcoma grows into the vagina, it is often felt that there is a lump protruding from the vagina. (3) Tumor pressure may cause urination disorder and pain in the lower back and abdomen. (4) Examination may reveal that the uterus is obviously enlarged and soft, and sometimes there is infiltrating mass in the pelvis. If it is grape sarcoma, it may protrude from the cervical opening or vagina, brittle and soft. (5) Abdominal pain: It is also a more common symptom. Due to the rapid growth of the fibroids, the abdomen is distended or vaguely painful. (6) If the tumor is large, it may compress the bladder or rectum and cause irritation, and compression of the veins may cause swelling of the lower limbs; in advanced stage, patients may have emaciation, anemia, fever, general failure, and pelvic mass infiltrating the pelvic wall. This disease is sometimes easily confused with uterine fibroids and sometimes misdiagnosed as endometrial cancer. Ancillary diagnoses such as ultrasound, CT, arteriography or lymphography can assist in the diagnosis. Pathological changes Uterine smooth muscle sarcoma Uterine smooth muscle sarcoma is the most common type of uterine sarcoma in China, accounting for about 0.64% of uterine smooth muscle tumors and about 45% of uterine sarcomas. It mainly comes from the smooth muscle fibers of the myometrium or uterine vascular wall and is prone to pelvic vascular, lymph node or pulmonary metastases. The sarcoma is seen to grow diffusely with no obvious boundary with the myometrium. In the case of myxosarcoma sarcomatous changes spread from the center to the periphery. The section loses its swirling structure and often appears as a uniform piece or fish-like. The color is grayish-yellow or yellowish-white, and more than half of them see hemorrhagic necrosis. Microscopically, smooth muscle cells are seen to be proliferating, with cells of different sizes, disorganized arrangement of uterine sarcoma, nuclear anisotropy, chromatin with many, deep staining and uneven distribution, and nuclei with obvious multinucleated giant cells. In addition, uterine smooth muscle sarcoma can be divided into the following subtypes: (1) epithelioid smooth muscle tumor or smooth muscle cell tumor or clear cell smooth muscle tumor: this tumor has less nuclear schizophrenic phase, usually <3/10 HPF, and can infiltrate the surrounding muscular layer, however, rarely infiltrates the blood vessels. Some of them are benign and most of them are potentially malignant or malignant. (2) Mucinous smooth muscle sarcoma: This tumor lacks the morphology of general smooth muscle sarcoma, and the microscopic morphology is benign with few cells and obvious mucinous interstitial changes. Endometrial mesenchymal sarcoma (a) Low-grade malignant endometrial mesenchymal sarcoma: also known as endolymphatic mesenchymal ectopic or endometrial mesenchymal ectopic disease. It is rare. There is a tendency for metastasis to parametrial tissues and, less frequently, lymphatic and pulmonary metastases. The spherical enlargement of the uterus with multiple granular and small clustered protrusions is seen by the naked eye, and the texture is elastic like rubber. The endometrial layer of the uterus was dissected to reveal a polypoid mass, yellow, with a smooth surface, uniform cut surface and no swirling arrangement. Microscopically, the endometrial mesenchymal cells were seen to invade between the muscle bundles of the myometrium, with little cell pulp, little cell isotype and little nuclear division phase, usually less than 3/10 HPFs. (b) Highly malignant endometrial mesenchymal sarcoma: rare and highly malignant. The tumor is seen with the naked eye to protrude into the lumen in the form of polyps, soft, grayish-yellow, fish-like in cut surface, with localized hemorrhagic necrosis and infiltration into the muscular layer. Microscopically, the endothelial mesenchymal cells were highly proliferated, and the glands were reduced and disappeared. The tumor cells are dense, round or spindle-shaped, with many nuclear fission phases, usually exceeding 10/10 HPFs, with an average of 25/10 HPFs and a maximum of 78/10 HPFs. (c) Malignant mixed mesodermal tumors of the uterus are not uncommon. The tumor contains both sarcoma and carcinoma components and is also called carcinosarcoma. The tumor is seen by the naked eye growing from the endometrium, protruding into the uterine cavity in the form of polyps, multiple or lobulated, with a wide base or forming a tip. In advanced stage, it infiltrates the surrounding tissues. The tumor is soft with smooth surface and small cystic cavity filled with mucus and grayish or grayish yellow in cut surface. Microscopically, both components of cancer and sarcoma are seen, and transitional forms are visible. Uterine sarcoma treatment instructions I. Surgical treatment: Most experts favor total hysterectomy. However, since uterine sarcoma may have direct parametrial spread and intravascular tumor embolism, a more extensive hysterectomy should be performed as far as possible without necessarily removing the pelvic floor lymph nodes. However, Belgred (1975) advocated that retroperitoneal pelvic and para-aortic lymph node biopsies should be taken at the same time as surgery to find out whether there are lymph node metastases. In case of cervical sarcoma or cervical sarcoma that has invaded the cervix, extensive hysterectomy should be performed with removal of the pelvic floor lymph nodes. For endometrial stromal sarcoma, preoperative radium therapy is recommended before total hysterectomy. In low-grade malignant uterine sarcoma (such as certain smooth muscle sarcomas and endolymphatic stromal lesions), which has the tendency of isolated local spread and central pelvic recurrence, extensive hysterectomy with bilateral adnexal resection should be performed, although the benefits of such surgical management are not yet conclusive, theoretically, local recurrence can be reduced by more extensive removal of the primary tumor. Lymph node metastasis is rare in low-grade malignant sarcoma, so lymph node dissection is performed only when enlarged lymph nodes are found intraoperatively or when lymph node metastasis is suspected. Recurrent pelvic foci of low-grade malignant sarcoma can often be successfully resected repeatedly whenever possible to improve the survival rate of patients. Partial or total pelvic exenteration may occasionally be used for metastases to the bladder or/and rectum. In young women with limited, non-infiltrating tumors, preservation of normal ovaries may be considered and the prognosis is not significantly different from that of resected cases. However, preservation of the ovaries is contraindicated in patients with uterine stromal sarcoma because of the higher chance of extrauterine metastasis. In highly malignant uterine sarcomas (certain smooth muscle sarcomas, endometrial stromal sarcomas and all mixed mesodermal sarcomas), because of their early lymphatic, local and hematogenous metastases, extensive surgery has been abandoned and only total hysterectomy and bilateral adnexal resection is performed, with additional radiation therapy before or after surgery. However, the issue of additional radiation therapy for smooth muscle sarcoma remains controversial, as it not only fails to improve patient survival, but also affects subsequent chemotherapy. Generally, after completion of surgery or surgery plus radiotherapy, additional chemotherapy should be considered for all patients. After detailed relevant examination, it is clear that only one side of the lung with isolated metastasis is feasible to be surgically removed, and there is about 25% 5-year survival rate. Radiotherapy: Because of the low sensitivity of uterine sarcoma to radiation, it is reported in the literature that there are few 5-year survivors with the application of radiotherapy alone. The efficacy of radiotherapy for endometrial stromal sarcoma and mixed mesodermal sarcoma of the uterus is better than that of smooth muscle sarcoma, and Gilbert believes that endometrial stromal sarcoma should be supplemented with radiotherapy before and after surgery. Badib reported that the 5-year survival rate increased from 57% to 74% in patients with various types of uterine sarcomas (clinical stage I) treated with surgery combined with radiotherapy compared with surgery alone. For patients with advanced sarcoma with metastasis or recurrence, 60-drill or deep X-ray is generally advocated as palliative treatment to prolong life. Chemotherapy Many cytotoxic anticancer drugs are effective against metastasis and recurrence of uterine sarcoma. The effect rate (response rate) of combined chemotherapy with cyclophosphamide, tuberculin, adriamycin, etc. alone and VAC (vincristine actinomycin D-cyclophosphamide) is 25-35% (related to cancer cell type). Some recurrent stromal sarcomas have been shown to respond to progesterone therapy. The combination of surgery, 60-drill radiotherapy, and oral high-dose 18-methylnortriptyline has also achieved better results in some cases of embryonal rhabdomyosarcoma of the genital tract in young girls. Uterine sarcoma prevention instructions Indiscriminate use of radiation therapy for benign pelvic lesions should be avoided; excessive exposure to radiation may lead to the development of sarcoma and should not be ignored. In addition, since early detection and diagnosis of sarcoma is more difficult, pelvic examinations and other ancillary examinations should preferably be performed every six months in women around menopause. Women of any age with abnormal vaginal discharge or lower abdominal discomfort should be promptly examined. Uterine sarcoma The factors affecting the prognosis are: (1) clinical stage; (2) pathological type; (3) histological grading; (4) age: those with postmenopausal onset are worse and vice versa; (5) those with sarcomatous uterine fibroids have a better prognosis; (6) treatment: if surgery can remove the tumor more completely, postoperative supplementation with radiotherapy and chemotherapy can improve the five-year survival rate. If the tumor cannot be removed surgically at late stage, despite the use of radiotherapy and chemotherapy, the patient will die within 1 year. Prevention: Indiscriminate use of radiation therapy should be avoided for benign pelvic lesions. Excessive exposure to radiation may lead to the development of sarcoma and should not be ignored. In addition, since early detection and diagnosis of sarcoma is more difficult, pelvic examinations and other ancillary examinations should preferably be performed every six months in women around menopause. Women of any age with abnormal vaginal discharge or lower abdominal discomfort should be promptly examined. Uterine sarcoma and birth control ring Uterine sarcoma can be stimulated by the ring if the ring can be used, which will trigger the growth of uterine sarcoma faster and very few of them may also become malignant to uterine cancer. Therefore, it is better to use condoms for contraception for uterine sarcoma. Usually, IUD is not recommended for inflammation of reproductive tract, tumor of reproductive organs, frequent menstruation, excessive menstrual flow, severe systemic diseases, loose cervical opening, severe laceration or severe uterine prolapse, and deformed uterus. Diagnostic basis of uterine sarcoma 1.Uterine sarcoma has no specific symptoms and signs, clinical manifestations have many similarities with other reproductive tract tumors, and the incidence is low, easy to be ignored, in order to improve the preoperative diagnosis rate, must be paid attention to; 2.Irregular vaginal bleeding with uterine enlargement before and after menopause or in young girls; 3.Rapidly increasing uterine fibroids, especially postmenopausal patients with uterine fibroids, should be considered the possibility of sarcoma transformation 4.Patients who have received previous radiation therapy and have sudden uterine enlargement with abnormal vaginal bleeding; 5.Cervical redundancy, diagnostic scraping, or hysterectomy specimens confirmed by pathology, (but negative diagnostic scraping cannot be excluded).