|Classification and external resources|
Leiomyosarcoma of the adrenal vein. Coronal view of abdominal MRI. Tumor (arrow) extends from the superior pole of the right kidney to the right atrium.
Leiomyosarcoma (Gr. "smooth muscle connective tissue tumor"), also referred to as LMS, is a malignant (cancerous) smooth muscle tumor. It must not be confused with leiomyoma, which is a benign tumor originating from the same tissue.
Leiomyosarcoma is a relatively rare form of cancer, and accounts for between 5–10% of soft tissue sarcomas, which are in themselves relatively rare. 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 or radiation. The best outcomes occur when it can be removed surgically with wide margins early, while small and still in situ.
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. It is therefore possible for leiomyosarcomas to appear at any site in the body (including the breasts); they are most commonly found in the uterus, stomach, small intestine and retroperitoneum.
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, also 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 where there is a blood vessel.
Grossly, 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.
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.
Notable people who have had leiomyosarcoma include:
- Padma L. Atluri — Writer for television series Men In Trees, 90210.
- Leicester City footballer Keith Weller who made over 300 appearances for the Foxes, scoring 47 goals. Also made 4 appearances for England, scoring 1 goal 
- Katie Price (Jordan)
- Canadian public health physician Sheela Basrur (1956–2008), who developed uterine leiomyosarcoma in 2006.
- American actress Diana Sands.
- Canadian comedian Irwin Barker, who was featured in a documentary, "That's my Time", which chronicled his battle with leiomyosarcoma. In Barker's own words. "Cancer has my body but not my spirit, and I'll continue to make jokes, not so much about cancer, but in spite of it."
- E. J. McGuire Long time professional ice hockey coach, scout, and VP of the NHL Central Scouting Bureau
- Weaver MJ, Abraham JA (2007). "Leiomyosarcoma of the Bone and Soft Tissue: A Review". ESUN 4 (2).
- "Basic info". LMS leiomyosarcoma.info.
- Arnold LM, Burman SD, O-Yurvati AH (April 2010). "Diagnosis and management of primary pulmonary leiomyosarcoma". J Am Osteopath Assoc 110 (4): 244–6. PMID 20430913.
- Piovanello P, Viola V, Costa G et al. (2007). "Locally advanced leiomyosarcoma of the spleen. A case report and review of the literature". World J Surg Oncol 5 (1): 135. doi:10.1186/1477-7819-5-135. PMC 2221972. PMID 18045454.
- "About Chemotherapy". LMS leiomyosarcoma.info. August 2002.
- Abu-Rustum, N. R.; Curtin, J. P.; Burt, M.; Jones, W. B. (1997). "Regression of uterine low-grade smooth-muscle tumors metastatic to the lung after oophorectomy". Obstetrics and gynecology 89 (5 Pt 2): 850–852. doi:10.1016/S0029-7844(97)00033-1. PMID 9166348.
- Hardman, M. P.; Roman, J. J.; Burnett, A. F.; Santin, A. D. (2007). "Metastatic Uterine Leiomyosarcoma Regression Using an Aromatase Inhibitor". Obstetrics & Gynecology 110 (2 Pt 2): 518–520. doi:10.1097/01.AOG.0000267533.56546.c2. PMID 17666649.
- "Leicester legend Weller mourned". BBC Online. 2004-11-13. Retrieved 2010-05-14.
- "Jordan treated for cancer". BBC Online. 2002-08-11. Retrieved 2009-10-30.
- Gillespie, Kerry (2008-04-12). "'Can't ever give up hope,' Basrur says". The Toronto Star. Retrieved 2010-01-08.
- Two Detailed Review Articles on Leiomyosarcoma
- LMS leiomyosarcoma.info Comprehensive reference site for information on leiomyosarcoma
- National Leiomyosarcoma Foundation
- Leiomyosarcoma Direct Research Foundation
- Sloan Kettering website
- #2434 (Pathology images)
- Gastrointestinal Stromal Tumors at eMedicine
- Live Leiomyosarcoma Video (Gupta Gastro Associates Unique Findings)