Uterine Sarcoma

Kristin Janson Redmond and Fariba Asrari

Background

What % of uterine malignancies are sarcomas?

Sarcomas account for ~4% of uterine malignancies.

What are the 3 most common histologic subtypes of uterine sarcoma?

Most common uterine sarcomas (in order of frequency):

Carcinosarcoma, also referred to as malignant mixed mullerian tumor (MMMT)
Leiomyosarcoma (LMS)
Endometrial stromal sarcoma (ESS)

How does uterine sarcoma typically present?

Typical presentation by histologic subtype:

MMM: vaginal bleeding
LMS and ESS: similar Sx and signs as uterine fibroids

What is the incidence of nodal mets?

MMM: 30% (20%–38%), even in clinically early-stage Dz
LMS: 8% (6.6%–9.1%), usually associated with extrauterine Dz
ESS: traditionally thought to be low (A recent study of 831 pts with ESS showed a 10% incidence.)

Note: The nodal mets and response rate to cisplatinum are similar in MMM and endometrial adenocarcinoma.

How does the risk of DM compare between endometrial cancer and uterine sarcoma?

In general, uterine sarcoma has a higher rate of metastatic Dz than endometrial cancer.

What is the most common site of mets in uterine sarcoma?

In uterine sarcoma, the most common site of mets is the lung.

For which histologic subtype of uterine sarcoma is grade most important?

Grade is most important for ESS. Low-grade ESS is a hormone-sensitive low-grade malignancy with an indolent course, whereas high-grade ESS is characterized by an aggressive clinical course that cannot be differentiated from other high-grade uterine sarcomas such as LMS and MMM.