Descripción general
Uterine sarcoma is a rare cancer that starts in the muscle or connective tissue of the uterus. It is a type of sarcoma, which is a cancer that develops in bone or soft tissue.
Uterine sarcomas make up about 5% of uterine cancers. Most uterine cancers are endometrial cancers, which start in the lining of the uterus, called the endometrium. Because uterine sarcomas start in different tissues of the uterus, they can behave differently from endometrial cancers.
There are several types of uterine sarcoma. Your healthcare team looks at the type, grade and stage of your cancer to better understand how it may behave and which treatments may be most helpful for you. Some types grow slowly. Others can grow and spread more quickly.
You may hear the term "carcinosarcoma" when learning about uterine sarcoma. Carcinosarcoma was once grouped with uterine sarcoma. It is now considered a type of carcinoma, rather than a sarcoma.
Types
Types of uterine sarcoma include:
- Uterine leiomyosarcoma. Uterine leiomyosarcoma (LMS) starts in the myometrium, the muscle layer of the uterus. It is the most common type of uterine sarcoma. It can grow and spread quickly.
- Endometrial stromal sarcoma. Endometrial stromal sarcoma (ESS) starts in the connective tissue that supports the lining of the uterus. ESS can be low grade or high grade. Low-grade ESS usually grows more slowly than high-grade ESS.
- Undifferentiated uterine sarcoma. This cancer can start in the lining or muscle of the uterus. It tends to grow and spread quickly.
- Uterine adenosarcoma. This cancer contains gland cells mixed with cancerous connective tissue cells. Many adenosarcomas are low grade. Some have a feature called sarcomatous overgrowth. This means more than 25% of the tumor is sarcoma. These tumors tend to grow faster.
Metastatic uterine leiomyosarcoma is a cancer that has spread from the uterus to another part of the body. For example, uterine leiomyosarcoma can spread to places such as the lungs, bones or liver.
Síntomas
Uterine sarcoma may not cause symptoms when the cancer is small. When symptoms occur, they can be hard to tell from symptoms of other conditions, including uterine fibroids.
Symptoms of uterine sarcoma may include:
- Vaginal bleeding or spotting between periods.
- Heavier or longer periods.
- Vaginal bleeding after menopause.
- Pelvic or abdominal pain.
- A lump, swelling, pressure or feeling of fullness in the abdomen or pelvis.
- Vaginal discharge.
- Needing to urinate more often.
- Constipation or trouble passing stool.
Symptoms cannot tell you what stage a uterine sarcoma is. Some cancers are found while they are small. Others do not cause noticeable symptoms until they have grown or spread.
When to seek care
Make an appointment with a healthcare professional if you have unusual vaginal bleeding or spotting. This includes any vaginal bleeding after menopause. Also make an appointment if you have another new symptom that concerns you.
These symptoms are more often caused by conditions other than uterine sarcoma. Getting them checked can help find the cause.
Causas
Most uterine sarcomas are not known to be inherited or to run in families. In most cases, the cause is not known.
Cancer starts when changes happen in a cell's DNA. These changes can affect how the cell grows and divides. Different types of uterine sarcoma can have different gene changes. Many of these gene changes develop only in the tumor cells.
Rarely, a person can inherit a gene change that increases the risk of uterine sarcoma. For example, inherited changes in the RB1 gene have been linked to this risk. These gene changes also are associated with hereditary retinoblastoma.
Factores de riesgo
Some things may increase the chance of uterine sarcoma. These are called risk factors. Risk factors include:
- Age. Uterine sarcoma is diagnosed most often after age 40. The average age at diagnosis is about 60.
- Previous radiation therapy to the pelvis. Uterine sarcoma can develop years after radiation treatment for another cancer.
- Tamoxifen. Taking tamoxifen to prevent or treat breast cancer slightly increases the risk of uterine cancers, including uterine sarcoma.
- Certain inherited cancer syndromes. Rare inherited conditions, including hereditary retinoblastoma and hereditary leiomyomatosis and renal cell carcinoma syndrome, have been linked to a higher risk of uterine sarcoma.
Having one or more risk factors does not mean you will develop uterine sarcoma. Many people with uterine sarcoma have few or no known risk factors.
Aug. 22, 2026