Leiomyosarcoma is a malignant (

cancerous Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...

)

smooth muscle tumor Smooth muscle tumours show a smooth muscle differentiation. There are two main types of smooth muscle tumour: the benign leiomyoma and the malignant leiomyosarcoma Leiomyosarcoma is a malignant (cancerous) smooth muscle tumor. A benign tumor orig ...

. A

benign tumor A benign tumor is a mass of cells (tumor) that does not invade neighboring tissue or metastasize (spread throughout the body). Compared to malignant (cancerous) tumors, benign tumors generally have a slower growth rate. Benign tumors have re ...

originating from the same tissue is termed leiomyoma. While leiomyosarcomas are not thought to arise from leiomyomas, some leiomyoma variants' classification is evolving. About one in 100,000 people are diagnosed with leiomyosarcoma (LMS) each year. LMS is one of the more common types of

soft-tissue sarcoma A soft-tissue sarcoma (STS) is a malignant tumour, a type of cancer, that develops in soft tissue. A soft tissue sarcoma is often a painless mass that grows slowly over months or years. They may be superficial or deep-seated. Any such unexplaine ...

, representing 10 to 20% of new cases. (Leiomyosarcoma of the bone is more rare.)

Sarcoma A sarcoma is a malignant tumor, a type of cancer that arises from transformed cells of mesenchymal ( connective tissue) origin. Connective tissue is a broad term that includes bone, cartilage, fat, vascular, or hematopoietic tissues, and sar ...

is rare, consisting of only 1% of

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

cases in adults. Leiomyosarcomas can be very unpredictable; they can remain dormant for long periods of time and recur after years. It is a resistant cancer, meaning generally not very responsive to

chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...

or radiation. The best outcomes occur when it can be removed surgically with wide margins early, while small and still ''

in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

''.

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, so leiomyosarcomas can appear at any site in the body. They are most commonly found in the

uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

, small intestine and

retroperitoneum The retroperitoneal space (retroperitoneum) is the anatomical space (sometimes a potential space) behind (''retro'') the peritoneum. It has no specific delineating anatomical structures. Organs are retroperitoneal if they have peritoneum on their ...

. Uterine leiomyosarcomas come from the smooth muscle in the muscle layer of the uterus. Cutaneous leiomyosarcomas derive from the pilo-erector muscles in the skin. Gastrointestinal leiomyosarcomas might come from smooth muscle in the 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 The tunica media (New Latin "middle coat"), or media for short, is the middle tunica (layer) of an artery or vein. It lies between the tunica intima on the inside and the tunica externa on the outside. Artery Tunica media is made up of smooth ...

). Thus, a leiomyosarcoma can have a primary site of origin anywhere in the body from a blood vessel. The tumors are usually hemorrhagic and soft and microscopically marked by pleomorphism, abundant (15–30 per 10 high-power fields) abnormal mitotic figures, and coagulative tumor cell necrosis. The differential diagnosis, which includes spindle cell carcinoma, spindle cell melanoma,

fibrosarcoma Fibrosarcoma (fibroblastic sarcoma) is a malignant mesenchymal tumour derived from fibrous connective tissue and characterized by the presence of immature proliferating fibroblasts or undifferentiated anaplastic spindle cells in a storiform pat ...

, malignant peripheral nerve sheath tumor and even biphenotypic sinonasal sarcoma, is wide.

Diagnosis

Diagnosis of LMS is made by performing a soft-tissue biopsy and examining its histopathology.

Treatment

Surgery, with as wide a margin of removal as possible, has generally been the most effective and preferred way to attack LMS. If surgical margins are narrow or not clear of tumor, however, or in some situations where tumor cells were left behind, chemotherapy or radiation has been shown to give a clear survival benefit. 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 Doxorubicin, sold under the brand name Adriamycin among others, is a chemotherapy medication used to treat cancer. This includes breast cancer, bladder cancer, Kaposi's sarcoma, lymphoma, and acute lymphocytic leukemia. It is often used toge ...

ifosfamide Ifosfamide (IFO), sold under the brand name Ifex among others, is a chemotherapy medication used to treat a number of types of cancer. This includes testicular cancer, soft tissue sarcoma, osteosarcoma, bladder cancer, small cell lung cancer, ...

and doxorubicin combination/

gemcitabine Gemcitabine, with brand names including Gemzar, is a chemotherapy medication. It treats cancers including testicular cancer, breast cancer, ovarian cancer, non-small cell lung cancer, pancreatic cancer, and bladder cancer. It is administered by ...

and

docetaxel Docetaxel (DTX or DXL), sold under the brand name Taxotere among others, is a chemotherapy medication used to treat a number of types of cancer. This includes breast cancer, head and neck cancer, stomach cancer, prostate cancer and non-small-cell ...

/ trabectedin;

pazopanib Pazopanib, sold under the brand name Votrient, is an anti-cancer medication marketed worldwide by Novartis. It is a potent and selective multi-targeted receptor tyrosine kinase inhibitor that blocks tumour growth and inhibits angiogenesis. It ha ...

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.

Notable cases

People who have had leiomyosarcoma include: * Leicester City footballer Keith Weller, who made over 300 appearances for the Foxes, scored 47 goals. Also, he made four appearances for England, scoring one goal. *

Katie Price Katrina Amy Alexandra Alexis Price (''née'' Infield; born 22 May 1978) is an English media personality and model. She gained recognition in the late 1990s for her glamour modelling work and had regular appearances on Page 3 in the British ...

* Canadian public-health physician Sheela Basrur (1956–2008) developed uterine leiomyosarcoma in 2006. * American actress

Diana Sands Diana Patricia Sands (August 22, 1934September 21, 1973) was an American actress, perhaps most known for her portrayal of Beneatha Younger, the sister of Sidney Poitier's character, Walter, in the original stage and film versions of Lorraine Han ...

* 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. * E. J. McGuire, long-time professional ice hockey coach, scout, and vice president of the

National Hockey League The National Hockey League (NHL; french: Ligue nationale de hockey—LNH, ) is a professional ice hockey league in North America comprising 32 teams—25 in the United States and 7 in Canada. It is considered to be the top ranked professional ...

Central Scouting Bureau *

Ellis Avery Ellis Avery (born Elisabeth Atwood; October 25, 1972 – February 15, 2019) was an American writer. She won two Stonewall Book Awards (the only author to have done so), one in 2008 for her debut novel '' The Teahouse Fire'' and one in 2013 for he ...

, American writer, two-time winner of the

Stonewall Book Award The Stonewall Book Award is a set of three literary awards that annually recognize "exceptional merit relating to the gay/lesbian/bisexual/transgender experience" in English-language books published in the U.S. They are sponsored by the Rainbow ...

* 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. * Irene Hirano Inouye, founding President of the U.S.-Japan Council, a position she held ever since she helped create the organization in 2009 (see her Wikipedia entry for more information).

References

External links