[2] When considering LMS specifically in the context of the uterus, it affects approximately 6 individuals per 1 million people in the United States each year.

The best outcomes occur when the tumor tissue can be removed surgically at an early stage, while it is small and has not yet spread from the original site (it remains in situ).

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).

[2] Some of the symptoms include nausea and vomiting, palpable lumps, pain, bleeding and unintentional weight loss.

Chemotherapy regimens include: doxorubicin/ifosfamide and doxorubicin combination/gemcitabine and docetaxel/trabectedin;[9] pazopanib is the targeted therapy used in metastatic leiomyosarcoma as second line and is well tolerated.

[15] For example, the FDA has warned against using morcellation for benign leiomyomas as those with unsuspected sarcomas are at risk of cancer spread.