What is a leiomyosarcoma?
A leiomyosarcoma is a rare cancerous tumor that forms in smooth muscle, which is found in blood vessels and hollow organs like the stomach and intestines. These involuntary muscles help move food, blood, saliva, and other substances through your body.
Leiomyosarcoma is a type of soft tissue sarcoma. While there are only about 1,200 new cases of leiomyosarcoma in the U.S. each year, it’s one of the more common soft tissue sarcomas. Very rarely, it can develop as a type of bone sarcoma, or bone cancer.
The tumors most often grow in the uterus and abdomen, but they can also appear near the spine, in major blood vessels, or in the arms or legs. This type of cancer typically develops around middle age or later.
Sarcoma providers at Penn Medicine’s Abramson Cancer Center are among the most experienced in the nation at treating leiomyosarcoma. We offer specialized surgeries, the latest drug therapies, and effective cancer monitoring after treatment focused on delivering the best possible outcomes.
Symptoms caused by leiomyosarcoma
You might not notice a leiomyosarcoma right away, but you may experience symptoms as the tumor grows or spreads and compresses or pushes on nearby organs or connective tissue. Tumors that become large can block blood flow to organs.
Symptoms vary depending on the tumor’s size and location. They may include:
- Changes in bowel or bladder function
- Gastrointestinal (GI) issues, including belly discomfort, bloating, internal bleeding, nausea, vomiting, or black stools
- Pain or swelling
- A visible lump under your skin
- Pain or discomfort during sex
- Unintended weight loss
- Unusual vaginal bleeding or vaginal discharge
What causes malignant tumors in smooth muscle?
Researchers don’t know what causes a leiomyosarcoma to develop. Some factors may increase your risk of developing one of these tumors.
Some people who previously received radiation therapy later develop a leiomyosarcoma as a rare side effect of treatment.
Some people inherit genetic changes from parents that cause syndromes tied to a range of health conditions, including sarcomas and other cancers. The syndromes with possible connections to leiomyosarcoma include:
- Hereditary retinoblastoma: In addition to raising the risk for the eye cancer retinoblastoma, this syndrome increases the chances of certain soft tissue sarcomas forming. These cancers include leiomyosarcoma, fibrosarcoma, and liposarcoma.
- Li–Fraumeni syndrome (LFS): While LFS is mainly connected to rhabdomyosarcoma, it can also rarely cause leiomyosarcoma.
How doctors diagnose leiomyosarcoma
To check for a leiomyosarcoma, our team starts by talking to you about your symptoms and performing a physical exam. If we suspect a tumor, imaging can provide details about the size and precise location.
Different scans are used for different parts of the body. For example, a CT scan is often used to look at the stomach or other organs, an MRI can show details of tumors near the spine and in the arms and legs, and a transvaginal ultrasound creates images of the uterus and other reproductive organs. Sometimes, a sample of the tumor is removed during an image-guided needle biopsy and studied by one of our specialized sarcoma pathologists to confirm a diagnosis. Leiomyosarcomas that grow in the uterus are usually identified after the entire tumor is carefully removed.
Removing leiomyosarcomas
Leiomyosarcoma treatment involves removing the tumor. The best results come from taking the leiomyosarcoma out in one piece, along with a small amount of surrounding tissue. In the abdomen, the operation may require taking out organs—most frequently the colon, kidneys, spleen, or pancreas. Uterine leiomyosarcoma is best removed during a hysterectomy that removes the whole uterus. We don’t remove the ovaries unless the cancer has spread.
At Penn Medicine, our surgeons remove the tumor while safely navigating around sensitive areas, like the spine, nerves, and blood vessels. To lower the chances of the cancer returning, our team may recommend radiation therapy, usually before surgery. Some larger, more aggressive tumors may benefit from chemotherapy, but it’s usually reserved for a leiomyosarcoma that has returned or spread. For a uterine leiomyosarcoma, hormonal therapy may help by blocking the effects of estrogen. Our treatment team may also recommend targeted therapy aimed at some of the pathways cancer uses to grow.
Doctors and scientists are also conducting sarcoma clinical trials to look at both new and existing drugs to treat leiomyosarcoma. These trials focus on leiomyosarcomas diagnosed as higher grade, meaning their cells look more aggressive under a microscope.
Deep experience in leiomyosarcoma care
Penn Medicine’s sarcoma care team treats hundreds of patients a year, including those with a leiomyosarcoma. Our experts have decades of combined experience from a variety of disciplines to bring you the most complete care. When you come here, you benefit from the expertise of surgeons, oncologists, musculoskeletal radiologists, pathologists, and other specialists. We also help drive innovation through our advanced sarcoma research. Our personalized approach means you’ll receive expert treatment tailored to your needs.
Rated “exceptional” by The National Cancer Institute
Penn Medicine’s Abramson Cancer Center is a world leader in cancer research, patient care, and education. Our status as a national leader in cancer care is reflected in our continuous designation as a Comprehensive Cancer Center by the National Cancer Institute (NCI) since 1973, one of 7 such centers in the United States. The ACC is also a member of the National Comprehensive Cancer Network, one of a select few cancer centers in the U.S., that are working to promote equitable access to high-quality, advanced cancer care.