Uterine carcinosarcomas (previously called malignant mixed Müllerian tumors) are dedifferentiated (metaplastic) carcinomas comprised of carcinomatous and sarcomatous elements arising from a single malignant clone. They are considered a high-risk variant of endometrial adenocarcinoma because carcinosarcomas share similarities in epidemiology, risk factors, and clinical behavior more closely with endometrial carcinoma as opposed to uterine sarcomas.
The clinical features, diagnosis, staging, and treatment of uterine carcinosarcoma will be discussed in this topic review. Other types of endometrial cancer and uterine sarcomas are reviewed separately. (See "Uterine sarcoma: Classification, clinical manifestations, and diagnosis" and "Overview of endometrial carcinoma" and "Classification and treatment of endometrial stromal tumors".)
EPIDEMIOLOGY AND RISK FACTORS
Uterine carcinosarcomas are rare tumors that account for less than 5 percent of all uterine malignancies . As an example, in the United States, the incidence of carcinosarcoma is approximately 1 to 4 per 100,000 women . Carcinosarcomas occur in older women; the median age at diagnosis ranges from 62 to 67 years . Blacks have a twofold higher incidence of uterine carcinosarcoma compared with non-Hispanic whites [4,5].
Uterine carcinosarcomas share similar risk factors with endometrial carcinomas. Both neoplasms are associated with obesity, nulliparity, and use of exogenous estrogen and tamoxifen [6-14]. Progestin-containing contraceptives are protective against both types of neoplasms. A history of exposure to pelvic radiation is also associated with an increased risk of developing uterine carcinosarcoma [15-17].
It is not possible to distinguish carcinosarcoma from endometrial carcinoma or uterine sarcoma based on clinical features. The diagnosis requires histologic evaluation. The typical features of carcinosarcoma are reviewed below. (See "Endometrial carcinoma: Clinical features and diagnosis", section on 'Clinical presentation'.)