Uterine sarcoma

# Overview
A uterine sarcoma is a malignant tumor that arises from the smooth muscle or connective tissue of the uterus. If the lesion originates from the stroma of the uterine lining it is an endometrial stromal sarcoma, and if the uterine muscle cell is the originator, the tumor is a uterine leiomyosarcoma. A lesion that also contains malignant tumor cells of epithelial origin is termed uterine carcinosarcoma (formerly called malignant mixed mesodermal/mullerian tumor).

# Classification
- Carcinosarcomas (mixed mesodermal sarcomas ).
- Leiomyosarcomas (30%).
- Endometrial stromal sarcomas (15%).
- Endometrial stromal sarcoma
- Malignant mixed mullerian tumor

# Histology
Tumoral entities include leiomyosarcomas, endometrial stromal sarcomas, carcinosarcomas and "other" sarcomas.
- If the lesion originates from the stroma of the uterine lining it is an endometrial stromal sarcoma.
- If the uterine muscle cell is the originator the tumor is a uterine leiomyosarcoma.
- Carcinosarcomas comprise both malignant epithelial and malignant sarcomatous components.

# Epidemiology
The vast majority of malignancies of the uterine body are endometrial carcinomas - only about 4% will be uterine sarcomas.

# Risk Factors
- The only documented etiologic factor in 10% to 25% of these malignancies is prior pelvic radiation therapy, which is often administered for benign uterine bleeding that began 5 to 25 years earlier.
- An increased incidence of uterine sarcoma has been associated with tamoxifen in the treatment of breast cancer.

# Signs and Symptoms
- Unusual or postmenopausal bleeding may be a sign of a malignancy including uterine sarcoma and needs to be investigated
- Pelvic pain
- Pelvic pressure
- Unusual vaginal discharge

# Diagnosis
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 mitosis per high power field.

# Staging
Uterine sarcoma is staged using the FIGO cancer staging system.
- Stage I: tumor confined to the corpus uteri
- Stage IA: no or less than half myometrial invasion
- Stage IB: invasion equal to or more than half of the myometrium
- Stage II : tumor invades cervical stroma but does not extend beyond the uterus
- Stage III: local and/or regional spread of the tumor
- Stage IIIA: tumor invades the serosa of the corpus uteri and/or adnexae
- Stage IIIB: vaginal involvement and/or parametrial involvement
- Stage IIIC: metastases to pelvic and/or para-aortic lymph nodes
- Stage IIIC1: positive pelvic nodes
- Stage IIIC2: positive para-aortic nodes with or without positive pelvic lymph nodes
- Stage IV: tumor invades bladder and/or bowel mucosa, and/or distant metastases
- Stage IVA: tumor invasion of bladder and/or bowel mucosa
- Stage IVB: distant metastasis, including intra-abdominal metastases and/or inguinal nodes

# Therapy
Surgery is often the principal means of diagnosis and is the primary treatment for all patients with uterine sarcoma. If the diagnosis is known, the extent of surgery is planned according to the stage of the tumor.
Stage I Uterine Sarcoma
- Standard treatment options:
- Surgery (total abdominal hysterectomy, bilateral salpingo-oophorectomy and pelvic and periaortic selective lymphadenectomy)
- Surgery plus pelvic radiation therapy
- Surgery plus adjuvant chemotherapy
- 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
Stage II Uterine Sarcoma
- Standard treatment options:
- Surgery (total abdominal hysterectomy, bilateral salpingo-oophorectomy, and pelvic and periaortic selective lymphadenectomy)
- Surgery plus pelvic radiation therapy
- Surgery plus adjuvant chemotherapy
Stage III Uterine Sarcoma
- Standard treatment options:
- Surgery (total abdominal hysterectomy, bilateral salpingo-oophorectomy, pelvic and periaortic selective lymphadenectomy, and resection of all gross tumor)
- Treatment options under clinical evaluation:
- Surgery plus pelvic radiation therapy
- Surgery plus adjuvant chemotherapy
Stage IV Uterine Sarcoma