Uterine leiomyosarcoma

Introduction to uterine leiomyosarcoma Uterine leiomyosarcoma is mainly derived from the smooth muscle cells of the myometrium. It can exist alone or in combination with leiomyoma. It is the most common uterine sarcoma. In theory, uterine leiomyosarcoma can be divided into primary and secondary. Some scholars believe that it is difficult to distinguish sarcoma from primary or secondary from clinical and pathological examination. It is not recommended to divide leiomyosarcoma into two. Primary and secondary. basic knowledge The proportion of illness: 0.0008% Susceptible people: women Mode of infection: non-infectious Complications: anemia

Causes of uterine leiomyosarcoma

Cause:

Primary leiomyosarcoma is derived from the smooth muscle tissue of the vascular wall of the uterine muscle wall or between the muscle walls. This sarcoma is diffusely growing, with no obvious boundaries between the uterine wall and no capsule. Secondary leiomyosarcoma is a malignant leiomyomas that are already present. According to statistics, about 0.5% of uterine fibroids become sarcoma, and only a few fibroids can be malignant in multiple myomas. Malignant transformation of fibroids often begins in the central part of the nucleus and extends to the periphery until the entire fibroid develops into a sarcoma, which often invades the capsule. It has been reported in the literature that some patients have a history of radiation therapy due to benign diseases or malignant tumors, most of which occurred 10 years after radiation therapy.

Pathogenesis:

Gross specimen examination

(1) The uterus often increases in uniformity, and it can also be irregularly enlarged and soft.

(2) Most of the tumors are single, large in size, more common between the muscle walls, and less subserosal and submucosal.

(3) The tumor can have a clear pseudo-envelope, and it can also diffusely grow, and the boundary with the muscle layer is unclear.

(4) Cut surface: Due to rapid tumor growth, hemorrhage and necrosis may occur, and the cut surface is fish-like. The typical vortex structure disappears. When there is focal or flaky hemorrhage or necrosis, it is difficult to distinguish it from red degeneration of uterine fibroids.

Uterine leiomyosarcoma prevention

Regular physical examination, early detection, early treatment, and good follow-up. For benign lesions of the pelvic cavity, radiation therapy should be avoided indiscriminately. Excessive exposure to radiation may lead to the occurrence of sarcoma and should not be ignored. In addition, due to the early detection and diagnosis of sarcoma is difficult, it is best to have a pelvic examination and other auxiliary examinations every half year for women before and after menopause. Women of any age, if there is abnormal vaginal secretions or lower abdominal discomfort, should be promptly examined.

Uterine leiomyosarcoma complications Complications anemia

1, a large amount of bleeding, followed by anemia.

2. Secondary infection.

3. Transfer in the distance.

4. Recurrence.

Uterine leiomyosarcoma symptoms Common symptoms Lower abdominal pain Vaginal bleeding Abdominal mass weakness, weight loss, low fever

Symptom

Uterine leiomyosarcoma generally has no specific symptoms and can be characterized by symptoms similar to uterine fibroids.

(1) Irregular vaginal bleeding: Irregular vaginal bleeding is the most common symptom. It often lasts for many days, with a large amount or a small amount. It can also be accompanied by a sudden large amount of vaginal bleeding, which can occur in 2/3 patients.

(2) lower abdominal pain, falling and other discomfort: about half of the patients, due to the rapid development of sarcoma, the tumor grows rapidly, often abdominal pain, which is due to excessive tumor expansion or intratumoral hemorrhage, necrosis, or sarcoma invasion through the uterine wall , causing rupture of the serosa layer and acute abdominal pain.

(3) Abdominal mass: The uterine fibroids grow rapidly and the uterine sarcoma may be considered when the lower abdomen touches the mass. Especially after the postmenopausal fibroids do not shrink, or instead increase, it should be considered as malignant.

(4) compression symptoms: when the tumor is large, it will compress the bladder or rectum, and there will be symptoms such as urgency, frequent urination, urinary retention, constipation, etc. If the pelvic cavity is pressed, it will affect the veins and lymphatic reflux of the lower extremities, and symptoms such as lower extremity edema may occur.

(5) Other symptoms: In the advanced stage of sarcoma, there may be symptoms such as weight loss, general malaise, anemia, and low fever. If you transfer to the lungs, you will cough and hemoptysis. If you transfer to the brain, you may have headaches and lower limb paralysis.

There are data showing that common symptoms of uterine leiomyosarcoma include irregular vaginal bleeding (67.2%), vaginal discharge (23.9%), abdominal mass (37.3%), lower abdominal pain (26.4%), and compression symptoms (22.4%).

2. Transfer

There are three main types of uterine leiomyosarcoma metastasis.

(1) Hematogenous dissemination: It is the main metastasis pathway, and it is transferred to the liver and lungs through blood circulation. Therefore, the distant metastasis of liver and lung of uterine leiomyosarcoma is more common. In clinical follow-up review, close attention should be paid.

(2) direct infiltration: sarcoma can directly invade the muscular layer, and even reach the serosa layer of the uterus, causing intra-abdominal dissemination and ascites.

(3) Lymph node metastasis: relatively few, especially in the early stages, therefore, it is advocated that early patients do not have to undergo lymph node resection.

Uterine leiomyosarcoma examination

1. Gynecological examination:

(1) Sarcoma is located in the submucosal, muscular and subserosal or broad ligaments of the uterus, more common between the muscle walls, less subserosal and submucosal.

(2) Generally, the uniformity is increased, and most of them are single and large in volume. It is softer than uterine fibroids and can coexist with uterine fibroids.

(3) The tumor may have a clear pseudo-envelope, or diffuse growth, and the boundary between the muscle layer and the muscle layer is unclear.

(4) Uterine sarcoma grows rapidly, especially after menopause. If the growth of the original uterine fibroids suddenly increases, the possibility of malignancy should be considered.

(5) Patients with advanced stage can be transferred to the pelvic and abdominal organs, and ascites can occur.

2, the characteristics of the microscope

(1) abnormal cell proliferation:

Smooth muscle cell proliferation is active, bleeding, necrosis, disordered arrangement, fish-like, vortex-like arrangement disappears.

(2) Cellularity:

The cell size and shape are inconsistent, the nuclear atypia is obvious, the chromatin is more, the dyeing is deep, and the distribution is uneven.

Classification: According to cell morphology, it is divided into spindle cell type, round cell type, giant cell type and mixed type.

(3) Pathological mitosis:

Low malignancy: mitotic figures 5 /10 HPFs (high power field of view).

Highly malignant: mitotic figures are 10/10 HPFs.

(4) necrosis:

Coagulative necrosis is the main cause.

Characteristics: The necrotic foci and the surrounding tissue are suddenly transformed, and no connective tissue with granulation tissue or hyaline degeneration is an intermediate zone.

3, vaginal color Doppler ultrasonography

Mechanism: Neovascularization of tumor tissue, mainly endothelial cells, lack of smooth muscle, decreased blood flow resistance, and showed high diastolic blood flow and low impedance on Doppler ultrasound.

Only 66% of the vascular formation was observed around and/or in the central region of the uterine fibroids, with an average impedance index of 0.54 +/- 0.08.

4, diagnostic curettage

The uterine leiomyosarcoma lesions are mostly located between the muscle walls, and it is difficult to scrape the sarcoma tissue.

The diagnosis is negative, and the possibility of diagnosing sarcoma cannot be ruled out.

Diagnosis and differentiation of uterine leiomyosarcoma

diagnosis

1. Diagnosis based on medical history

(1) The symptoms of uterine leiomyosarcoma are not specific, so preoperative diagnosis is quite difficult.

(2) There is a history of uterine fibroids, the uterus increases rapidly, especially after menopause, not only does not shrink, but continues to increase, or with vaginal bleeding, abdominal pain and other symptoms, should consider the possibility of uterine sarcoma.

2. Sign diagnosis

(1) pelvic and abdominal mass, or ascites, abdominal pain and low back pain.

(2) Gynecological examination The mass may be hard or soft, and the surface may be uneven or nodular.

However, the diagnostic criteria for uterine leiomyosarcoma have not been uniform for a long time. Some scholars believe that the mitotic image is counted in the most active area of the tumor, and 10/HPFs are used as the criteria for distinguishing between benign and malignant. However, some scholars have suggested that the diagnosis of sarcoma should not only be Diagnosis based on the number of mitotic figures should be diagnosed according to the density of tumor cell proliferation, the degree of cell atypia and the number of mitotic figures. When the tumor cells are abundant, the degree of cell division with mitotic figures is above 5/10HPFs, or Severe heterotypic nucleus with more than 2/10HPF, or tumor cells invading the muscularis or vessels, and pathological mitotic figures, can be diagnosed as uterine leiomyosarcoma.

In recent years, gynecological pathologists believe that the diagnosis of uterine leiomyosarcoma should not only consider the degree of tumor cell proliferation, cell atypia and mitotic figures, but more importantly, the coagulative necrosis of the tumor, the diagnosis of the uterus cannot be diagnosed by any single indicator. For leiomyosarcoma, the above four indicators should be combined to make a diagnosis.

Regarding the problem of malignant transformation of leiomyosarcoma, some scholars believe that uterine fibroids can be secondary to sarcoma, which suggests that secondary leiomyosarcoma has the following characteristics:

1 malignant transformation often begins in the center of the fibroid, and the surrounding area is still benign.

2 of the multiple myomas often only 1 to 2 sarcoma changes, the rest are still benign.

3 The pseudo-envelope can often be seen under the naked eye and under the microscope.

The structure of sarcoma lesions and benign fibroids can be found in the same section or in the same tumor under 4 microscopes.

Differential diagnosis

The following situations are easily confused with uterine leiomyosarcoma and need to be identified.

1.Smooth muscle tumors uncertain malignant potential (STUMP)

Diagnostic Criteria: STUMP can be diagnosed if any of the following is true.

(1) The cells are mild to moderately heteromorphic, with mitotic figures such as 5-10 /10 HPFs, and no cell coagulative necrosis.

(2) The mitotic image is 15/HPF, but there is no cell density and heterotypic.

(3) There are fewer mitotic figures, and there are abnormal mitotic figures and coagulative necrosis of tumor cells.

The diagnostic criteria for malignant potential undetermined leiomyoma have not been unified. Peter (1994) and other retrospective analysis of 50 patients with uterine leiomyosarcoma, 32 of whom were still sarcoma, 3 were leiomyomas, and 15 were diagnosed as Malignant potential undefined type of leiomyoma, compared with the sarcoma group, the recurrence rate and mortality of the malignant potential undefined type of leiomyoma group are low, and can still survive for a long time after recurrence, but there are uncertainties and varied clinical processes. Age, lesion size, menopause and flow cytometry DNA can not predict the clinical process, chemotherapy did not show effective, surgical resection of recurrent metastases can improve survival time.

2. Epithelioid smooth muscle tumor (epithelioid smooth muscle tumor) also known as leiomyoblastoma (leiomyoblastoma) or clear cell smooth muscle tumor (clear cell smooth muscle tumor), a few are benign, mostly malignant or potentially malignant, morphologically difficult to distinguish Malignant, simple epithelioid leiomyomas are rare, mostly accompanied by spindle cell leiomyosarcoma, therefore, clinically should be more than a biopsy, often find a typical sarcoma lesions.

Pathological features:

(1) It is generally like a leiomyomas, but it has no braided structure and the boundaries are unclear.

(2) The tumor cells are mostly polygonal or round, diffuse into pieces or arranged into a nest, cord or plexiform, the cytoplasm of the tumor cells is transparent, the nucleus is round or oval, the nucleus is more regular, and the nucleus is less, generally less than 3 / HPFs.

(3) Tumor cells can invade the surrounding muscle layer, but rarely invade blood vessels.

3. Myxoid leiomyosarcoma is a rare special type of uterine leiomyosarcoma, which is characterized by a tumor-like cut surface, lack of leiomyomas, good morphology under the microscope, few cells, interstitial mucus Change, less nuclear division, but the tumor is infiltrating and growing, almost all malignant.

4. Benign metastasizing leiomyoma is rare. Patients have multiple leiomyomas. The fibroids can be transferred to the lungs, retroperitoneum, mediastinal lymph nodes, bone and soft tissues. The most common metastatic site is the lung. There are one or several leiomyomas nodules in the lungs, the larger ones can reach 10cm, the boundaries are clear, and there may be cystic changes. Some people think that benign metastatic leiomyomas are a kind of low-grade leiomyosarcoma. Clinically, The performance is a benign process, but metastasis can occur. The patient may have a history of surgery for uterine fibroids. Intrapulmonary lesions appear several years after surgery, but the uterus and lung lesions are benign. There are several theories about the cause of the disease:

1 iatrogenic spread.

2 Intravenous leiomyomatosis caused by pulmonary embolism.

3 The uterine fibroids of the initial operation were malignant, no serial sections were taken, and no small leiomyosarcoma lesions were found.

4 pulmonary leiomyomas.

Identification with primary leiomyoma in the lung:

1 benign metastatic leiomyomas associated with multiple intrauterine fibroids, intrapelvic and retroperitoneal lymph node metastasis.

2 shrinking during pregnancy, stop growth after menopause, and gradually shrink, therefore, benign metastatic leiomyomas are estrogen-related tumors, can be treated with anti-estrogen drugs.

5. disseminated peritoneal leiomyomatosis

Ieiomyomatosis peritonealis disseminata is a malignant, but benign, leiomyomatosis characterized by multiple leiomyomas, benign hyperplasia, and fibroids in the uterus. The surface of the peritoneum, omentum, mesentery, intestine, ovary and pelvic organs have multiple nodules of different sizes. The smaller ones are 1 to 8 mm in diameter and the larger ones are up to 8 cm in diameter. The appearance is like malignant planting, and some patients do not. With uterine fibroids, there are two reasons for the incidence:

1 fibroids occur in multiple centers, and are associated with high estrogen and low progesterone. Estrogen may be a predisposing factor. Estrogen stimulates the submucosal mesenchymal cells to metaplasia. This is currently recognized by most scholars. .

2 metastatic planting, this view is currently not established, because the nodules are under the peritoneal epithelium, and no extraperitoneal metastasis.

Microscopic examination showed that the nodules were composed of fusiform smooth muscle cells, and the muscle bundles were arranged in a spiral shape. The tumor cells were of uniform size, with no atypical changes, no giant cell formation, no nuclear fission or occasional, no vascular invasion, histologically. Benign, after the removal of the whole uterus and double attachments, the lesions can be retracted. It has been reported that some patients can naturally return to the disease, but they can also relapse. After recurrence, they are still benign. No special treatment is needed except surgery.

Has the following characteristics:

(1) The peritoneum of the pelvic and abdominal cavity is covered with leiomyomas nodules of different sizes, round, and the peritoneum is nodular or flaky thickening.

(2) The morphology under the microscope is benign leiomyomas, non-nuclear atypia and schizophrenia.

(3) Blacks, pregnancy, postpartum and oral contraceptives are prone to occur.

(4) Endometriosis is associated with fibroid nodules in approximately 1/5 of patients.

(5) The fibroids can disappear completely or partially after pregnancy or after ovariectomy, indicating that the disease is hormone dependent.

(6) The pathogenesis may be the metaplasia of subperitoneal stromal cells, 70% of cases are pregnant women or those who use exogenous hormones.

6. Intravenous leiomyomatosis is a rare fibroid with a common age of 42 to 45 years old. About 40% of patients have menstrual abnormalities and are accompanied by chronic pelvic pain.

There are two theories about the causes of this type of lesion:

1 smooth muscle tissue derived from the vein wall, proliferating and protruding into the venous cavity.

2 leiomyomas derived from the uterus, fibroids invade the veins and develop, and in this case there are many uterine fibroids.

According to statistics, about 75% of leiomyomatosis lesions do not exceed the broad ligament range, 25% of lesions extend beyond the broad ligament, and if the lesion spreads to the inferior vena cava and right atrium, it often leads to death.

Tumors have the following characteristics:

(1) The fibroids mainly grow in the vein, often extending along the uterine vein to the extrauterine vein, such as the ovarian vein, the vaginal vein and the broad ligament vein, etc., and some can reach the inferior vena cava, right heart, lung, causing death.

(2) The uterus is large, the muscle layer is thickened, and there are multiple nodular rubber-like masses.

(3) The tumor is located in the blood vessel.

(4) The surface of the intravascular fibroids is covered with endothelial cells. The fibroids are located in the vascular lumen or attached to the vessel wall. The fibroids are generally benign leiomyomas or epithelioid leiomyomas.

(5) fibroids may be associated with extensive edema degeneration, mucoid degeneration or glassy changes.

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