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Cancer Health Center

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It is possible that the main title of the report Leiomyosarcoma is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Leiomyosarcoma is a malignant (cancerous) tumor that arises from smooth muscle Cells There are essentially two types of muscles in the body - voluntary and involuntary. Smooth muscles are involuntary muscles - the brain has no conscious control over them. Smooth muscles react involuntarily in response to various stimuli. For example, smooth muscle that lines the walls of the digestive tract causes wave-like contractions (peristalsis) that aid in the digestion and transport of food. Smooth muscles in the salivary glands cause the glands to squirt saliva into the mouth in response to taking a bite of food. Smooth muscle in the skin causes goose bumps to form in response to cold.

Leiomyosarcoma is a form of cancer. The term "cancer" refers to a group of diseases characterized by abnormal, uncontrolled cellular growth that invades surrounding tissues and may spread (metastasize) to distant body sites via the bloodstream, the lymphatic system, or other means. Different forms of cancer, including leiomyosarcomas, may be classified based upon the cell type involved, the specific nature of the malignancy, and the disease's clinical course. Leiomyosa usually spreads via the bloodstream. It is very rare to see it in lymphatics.

Since smooth muscle is found all over the body, a leiomyosarcoma can form almost anywhere where there are blood vessels, heart, liver, pancreas, genitourinary and gastrointestinal tract, the space behind the abdominal cavity (retroperitoneum), uterus, skin. The uterus is the most common location for a leiomyosarcoma. Most leiomyosarcomas of the gastrointestinal tract are now reclassified as gastrointestinal stromal tumors (GIST - see below)

Leiomyosarcoma is classified as a soft tissue sarcoma. Sarcomas are malignant tumors that arise from the connective tissue, which connects, supports and surrounds various structures and organs in the body. Soft tissue includes fat, muscle, nerves, tendons, and blood and lymph vessels. The exact cause of leiomyosarcoma, including uterine leiomyosarcoma, is unknown.


American Cancer Society, Inc.
250 Williams NW St
Ste 6000
Atlanta, GA 30303
Tel: (404)320-3333
Tel: (800)227-2345
TDD: (866)228-4327

National Cancer Institute
6116 Executive Blvd Suite 300
Bethesda, MD 20892-8322
Tel: (301)435-3848
Tel: (800)422-6237
TDD: (800)332-8615

OncoLink: The University of Pennsylvania Cancer Center Resource
3400 Spruce Street
2 Donner
Philadelphia, PA 19104-4283
Tel: (215)349-8895
Fax: (215)349-5445

Sarcoma Foundation of America
9899 Main Street Ste 204
Damascus, MD 20872
Tel: (301)253-8687
Fax: (301)253-8690

Sarcoma Alliance
775 E. Blithedale #334
Mill Valley, CA 94941
Tel: (415)381-7236
Fax: (415)381-7235

Rare Cancer Alliance
1649 North Pacana Way
Green Valley, AZ 85614

Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311
TDD: (888)205-3223

76 Ellsworth Street
San Francisco, CA 94110
Tel: (415)826-0474

Northwest Sarcoma Foundation
P.O. Box 91460
Portland, OR 97291
Tel: (503)954-5740

For a Complete Report:

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site or email

Last Updated: 9/4/2012
Copyright 2008, 2012 National Organization for Rare Disorders, Inc.

WebMD Medical Reference from the National Organization for Rare Disorders

Last Updated: 8/, 015
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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