A leiomyosarcoma (LMS) is a rare malignant (cancerous) smooth muscle tumor. The word is . The stomach, bladder, uterus, blood vessels, and intestines are examples of hollow organs made up of smooth muscles where LMS can be located; however, the uterus and abdomen are the most common sites.

Although leiomyosarcomas are rare, they belong to the more common types of soft-tissue sarcoma, representing 10–20% of new cases.

Mechanism

Smooth muscle cells make up the involuntary muscles, which are found in most parts of the body, including the uterus, stomach and intestines, the walls of all blood vessels, and the skin. These are the areas where LMSs originate. LMSs also often develop in the retroperitoneal region which consists of the suprarenal glands, the kidney, and ureter. Just as it is not known what truly causes most sarcomas, LMSs have similarly complex karyotypes and it is suggested that because of the complexity, genomic instability might be the cause. Cutaneous leiomyosarcomas derive from the pilo-erector muscles in the skin. Gastrointestinal leiomyosarcomas might come from smooth muscle in the gastrointestinal (GI) tract, or alternatively, from a blood vessel. At most other primary sites—retroperitoneal extremity (in the abdomen, behind the intestines), truncal, abdominal organs, etc.—leiomyosarcomas appear to grow from the muscle layer of a blood vessel (the tunica media). Thus, a leiomyosarcoma can have a primary site of origin anywhere in the body from a blood vessel.]]

To diagnose LMS, a physical exam may be performed by one's physician, imaging tests such as MRI, CT, and PET scans can be performed, or tissue biopsies can also be completed where the histopathology of the removed tissue sample is examined. While LMS tends to be resistant to radiation and chemotherapy, each case is different and results can vary widely.

For metastatic (widespread) disease, chemotherapy and targeted therapies are the first choices.

Chemotherapy regimens include doxorubicin/ifosfamide and doxorubicin combination/gemcitabine and docetaxel/trabectedin; pazopanib is the targeted therapy used in metastatic leiomyosarcoma as second line and is well tolerated.

LMS of uterine origin often responds to hormonal treatments. As of 2020, several clinical trials for uterine LMS are active.

Uterine leiomyomas vs uterine leiomyosarcomas

Leiomyomas are benign smooth muscle tumors that have overlapping features with leiomyosarcomas. Although both originate from smooth muscle, leiomyomas notably do not mature to become leiomyosarcomas. Leiomyomas are seen in premenopausal women and are symptomatic 20–50% of the time, while leiomyosarcomas, the most common uterine sarcomas, are seen in older postmenopausal women, with 40-60 being the peak age incidence. Since leiomyomas are benign and mostly asymptomatic, minimally invasive treatment modalities are used to treat them.

Epidemiology

Leiomyosarcomas are rare. Sarcomas combined account for less than 1% of cancer diagnoses, and leiomyosarcoma accounts for around 10% of sarcoma diagnoses. Around 63% of uterine sarcomas, 20% of abdominal sarcomas, and 15% of sarcomas of the arms and legs are leiomyosarcomas.

  • Leicester City footballer Keith Weller, who made over 300 appearances for the Foxes, scoring 47 goals, made four appearances for England, scoring one goal.
  • Katie Price
  • Canadian public-health physician Sheela Basrur (1956–2008) developed uterine leiomyosarcoma in 2006.
  • American actress Diana Sands
  • The first year of treatment for leiomyosarcoma of Canadian comedian Irwin Barker was the subject of a 2008 television documentary, That's My Time; he died in 2010.
  • Linda Uttley (1966–2009), English rugby union footballer in the Women's England Team, was diagnosed with leiomyosarcoma in 2007 and died in 2009 at the age of 43.
  • Deborah Finck (1967–2025), TikToker and Nanny 911 star, was diagnosed with leiomyosarcoma in 2020 and died on January 14, 2025, at the age of 57.
  • Loni Anderson (1945–2025), American actress, died from metastatic uterine leiomyosarcoma on August 3, 2025, at the age of 79.

See also

  • Uterine sarcoma

References

  • Leiomyosarcoma Support & Direct Research Foundation