How Rare is Leiomyosarcoma?
Uterine sarcoma has a worldwide incidence of 0.5 to 3.3 cases per 100,000 women, Müllerin mixed tumors of 0.82 per 100,000 women, Leiomyosarcoma have an incidence of 0.64 per 100,000 women. Sarcomas of the endometrial stroma report an incidence of 0.19 per 100,000 women. They represent globally 3% to 4% of uterine tumors. There are few epidemiological studies to identify the risk factors. It is known that its presentation with greater frequency is in women of 40 to 60 years of age, the antecedent of intake of oral contraceptives and tamoxifen.
Parity, menarche and menopause are not conclusive. The history of pelvic radiation therapy represents a risk of 5% to 10%. According to the race, it is two to three times higher its incidence in African Americans.
Sarcomas of the uterus represent a diverse group of tumors, constituting only 1% of the malignant neoplasms of the female genital tract and occupy 3 to 8.4% of malignant uterine neoplasms. The following are the types of uterine sarcomas:
Leiomyosarcoma is the most frequent type of uterine sarcoma. It presents itself as a pelvic mass in 54% of cases, bleeding vagina in 56% and in 22% with pelvic pain.
From the histological point of view, they must be differentiated from atypical leiomyomas or from leiomyomas with mitotic activity. The tumoral necrosis is the key point in the diagnosis and must be differentiated of hyalinization and ulcerative necrosis.
Endometrial Stromal Sarcoma (ESS)
It represents 10 to 15% of sarcomas and 0.2% of all uterine tumors. It occurs more frequently between 40 and 55 years of age, transvaginal bleeding is the most common sign, although 25% are asymptomatic.
Also known as Sarcoma of the undifferentiated endometrial stroma, it has the characteristic of being a very high-grade neoplasm with a poor prognosis. It may or may not show transition with areas of low-grade endometrial stromal sarcoma and recently it has been subdivided into two categories depending on the cytological atypia in : a) sarcoma of the high-grade endometrial stromal a and b) undifferentiated sarcoma.
Immunohistochemistry studies are not useful for the diagnosis of neoplasia and it is considered an exclusion diagnosis after having ruled out other uterine tumors.
Other less frequent uterine sarcomas are the adenosarcomas, rhabdomyosarcomas and pecomas.
The main symptom is transvaginal bleeding (95%). It is characterized by a fluctuating quantity; it can be accompanied by pain, stench or symptoms of pelvic pressure.
Patients have different degrees of anemia. In the physical examination the doctors can find uterus increased in size. The main differential diagnosis of sarcoma is leiomyoma.
There is no screening method for these neoplasms. In general, the clinical data that suggest the presence of a uterine sarcoma, independently of the histological lineage, are a voluminous uterine tumor of rapid growth, transvaginal bleeding and pelvic pain.
From an image point of view, the diagnosis can be a problem especially in young women, since the suspicion of malignancy is not common because the gynecological alterations are associated to menstrual irregularities and abnormal genital bleeding.
The treatment of choice in uterine sarcomas is “optimal” surgery: in leiomyosarcomas, total hysterectomy (surgical extraction of the uterus), double adnexectomy and pelvic lymphadenectomy (surgical extraction of the lymph nodes), if they are enlarged. Regarding the adjuvant treatment, patients with stage I and II, radiotherapy increases local control, but does not seem to affect overall survival. Similarly, chemotherapy decreases the known high proportion of subclinical tumor dissemination, but there has been no improvement in overall survival either. In inoperable patients, with a relapsing or recurrent disease, the therapeutic alternatives are radiotherapy and palliative chemotherapy. In the differential diagnosis of fast-growing abdominal masses, uterine sarcoma should be a possibility to be taken into account.
Uterine sarcomas are rare tumors, which represent up to 4% of uterine tumors. Its prognosis is poor and there are few prospective studies of its treatment and clinical responses. Uterine sarcomas have a reserved prognosis, with favorable treatment rates with surgery. The role of adjuvant treatment is not clearly demonstrated.