The uterine sarcomas form a group of malignant tumors that arises from the smooth muscle or connective tissue of the uterus. They can be difficult to detect, as symptoms are common to other uterine conditions and no specific screening test has been developed. This presents an issue for treatment, as the cancer spreads quickly. Uterine sarcoma is rare and mostly occurs in post-menopausal women. The most common type, leiomyosarcoma, is twice as common in Black women as it is in white women. Uterine sarcoma condition is most commonly treated by radical hysterectomy. If cancer has spread beyond the uterus, radiation, chemotherapy, and hormonal therapy may be used. If detected in its early stages, survival rates for uterine sarcoma are 66% after 5 years. If cancer has spread beyond the uterus, the survival rate declines to approximately 13-34%.

Signs and symptoms

Clinically, uterine sarcomas and leiomyomas (fibroids) both have similar symptoms such as increased uterine size, abdominal pain and vaginal bleeding so it can be difficult to tell them apart. Unusual or postmenopausal bleeding may be a sign of uterine sarcoma and needs to be investigated. Other signs include pelvic pain, pressure, and unusual discharge. A nonpregnant uterus that enlarges quickly is suspicious. However, none of the signs are specific. Specific screening test have not been developed; a Pap smear is a screening test for cervical cancer and not designed to detect uterine sarcoma.

Histology

Tumoral entities include leiomyosarcomas, endometrial stromal sarcomas, carcinosarcomas and "other" sarcomas.

Diagnosis

By using T2*-weighted imaging, MRI is able to differentiate distinguishing features of leiomyomas from uterine sarcomas. Investigations by the physician include imaging (ultrasound, CAT scan, MRI) and, if possible, obtaining a tissue diagnosis by biopsy, hysteroscopy, or D&C. Ultimately the diagnosis is established by the histologic examination of the specimen. Typically malignant lesions have >10 mitosis per high power field. In contrast, a uterine leiomyoma as a benign lesion would have < 5 mitoses per high power field.

Classification

Leiomyosarcomas are now staged using the 2009 FIGO staging system (previously they were staged like endometrial carcinomas) at the time of surgery. Endometrial stromal sarcomas and uterine adenosarcomas are classified as above, with the exception of different classifications for Stage I tumors. Finally, malignant mixed Müllerian tumors, a type of carcinosarcoma, are staged similarly to endometrial carcinomas.

Management

Therapy is based on staging and patient condition and utilizes one or more of the following approaches. Surgery is the mainstay of therapy if feasible involving total abdominal hysterectomy with bilateral salpingo-oophorectomy. Other approaches include radiation therapy, chemotherapy, and hormonal therapy. Prognosis is relatively poor.

Epidemiology

Uterine sarcoma is rare, out of all malignancies of the uterine body only about 4% will be uterine sarcomas. Generally, the cause of the lesion is not known, however, patients with a history of pelvic radiation are at higher risk. Most tumors occur after menopause. Women who take long-term tamoxifen are at higher risk.