A uterine leiomyosarcoma is a rare malignant (cancerous) tumor that arises from the smooth muscle lining the walls of the uterus (myometrium). 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, the myometrium stretches during pregnancy to help accommodate the fetus and contracts during labor to help push out a baby during childbirth.
Uterine leiomyosarcoma is an extremely rare form of cancer, estimated to occur in 6 out of every 1,000,000 women in the United States each year. The average age at diagnosis is 51. Uterine leiomyosarcomas account for 1-2 percent of all malignant tumors of the uterus.
Symptoms of uterine leiomyosarcoma may vary from case to case depending upon the exact location, size, and progression of the tumor. Many women will not have any apparent symptoms (asymptomatic). The most common symptom is abnormal bleeding from the vagina and the uterus. Postmenopausal bleeding is an important factor that may indicate a uterine leiomyosarcoma.
Additional symptoms may occur including pressure or pain affecting the pelvis or stomach, abnormal vaginal discharge, and a change in bladder or bowel habits. General symptoms often associated with cancer include fatigue, fever, weight loss, and a general feeling of ill health (malaise).
Uterine leiomyosarcomas are malignant and may spread (metastasize) locally and to other areas of the body, especially the lungs and liver often causing life-threatening complications. Leiomyosarcomas recur in more than half of the cases sometimes within eight to 16 months of the initial diagnosis and treatment.
(Information from the National Organization of Rare Disorders/Diseases)