Malignant mixed Mullerian tumor (MMMT) of the uterus, also known a uterine carcinosarcoma, is the commonest (up to 50%) uterine sarcoma. They are thought to account for 2-8% of all malignant uterine cancers 1-2. The uterus is the commonest site for malignant mixed Mullerian tumors 1.
A uterine MMMT can be either homologous or heterologous.
Similar to MMMTs in general, they are composed or both carcinomatous (epithelial) and sarcomatous (mesodermal) components. Usually, the epithelial component dominates 2.
Prevalent subtypes for the epithelioid component include:
- endometrioid adenocarcinoma: most common epithelioid subtype 2
- clear cell carcinoma
- mucinous carcinoma
- papillary-serous carcinoma
Prevalent subtypes for the sarcomatoid component include:
Uterine MMMTs commonly present as an intracavitary mass with coexistent dilatation of the endometrial canal.
Often hyperechoic on ultrasound 1.
Often heterogeneously hypodense and ill-defined on contrast-enhanced CT 1. Dilatation of uterine cavity can be appreciated the vast majority of cases.
They are not considered to have a pathognomonic appearance on MRI, with appearances often indistinguishable from those of endometrial adenocarcinoma.
However reported general signal characteristics include 3.
- T1: predominantly isointense to both myometrium (~75%) and endometrium (~70%)
- hyperintense to myometrium (~90%)
- either hypo-intense (~55%) or isointense (~41%) to the endometrium
C+ dynamic contrast
- <1 min: hypointense (~40%) or isointense (33%) to myometrium
- 1-4 min: hypointense (~60%) to myometrium
- >4 min: isointense (56%) to myometrium
Treatment and prognosis
Like other malignant mixed Mullerian tumors, they are highly aggressive tumors and carry a poor prognosis.
General considerations include:
- 1. Teo SY, Babagbemi KT, Peters HE et-al. Primary malignant mixed mullerian tumor of the uterus: findings on sonography, CT, and gadolinium-enhanced MRI. AJR Am J Roentgenol. 2008;191 (1): 278-83. doi:10.2214/AJR.07.3281 - Pubmed citation
- 2. Ho SP, Ho TH. Malignant mixed Mullerian tumours of the uterus--a ten-year experience. Singapore Med J. 2002;43 (9): 452-6. - Pubmed citation
- 3. Bharwani N, Newland A, Tunariu N et-al. MRI appearances of uterine malignant mixed müllerian tumors. AJR Am J Roentgenol. 2010;195 (5): 1268-75. doi:10.2214/AJR.10.4419 - Pubmed citation
- 4. Mccluggage WG. Uterine carcinosarcomas (malignant mixed Mullerian tumors) are metaplastic carcinomas. Int. J. Gynecol. Cancer. 12 (6): 687-90. - Pubmed citation