Childhood Leiomyosarcoma

Leiomyosarcoma is a very rare, but very treatable cancer. It is a type of soft tissue sarcoma that grows in muscle tissue. In children, it usually grows in the gastrointestinal tract, which includes the stomach, small intestines, colon, appendix, rectum and anus. It can be difficult to detect because the tumor may be covered by other structures, such as skeletal muscle.

Dana-Farber/Boston Children’s Cancer and Blood Disorders Center provides comprehensive medical and surgical care for children with childhood leiomyosarcoma in our Bone and Soft Tissue Tumors Program.

• Leiomyosarcoma can spread (metastasize) to other areas of the body, but usually does not if it is removed early.
• Its cause is unknown but has been linked to genetics and inherited diseases.
• Children with AIDS are at risk for developing this kind of cancer.
• Girls and boys have equal risks of having leiomyosarcoma.
• It is extremely rare. There are only 20 to 30 cases of child leiomyosarcoma cases per year in the United States.
• A tumor may exist for a long time before being discovered.
• Treatment usually involves surgery and potentially radiation therapy and/or chemotherapy.
• Leiomyosarcoma is very treatable, with 80% success rate if the tumor is completely removed.

Types of childhood leiomyosarcoma include:

• Soft tissue leiomyosarcoma
• Cutaneous (skin) leiomyosarcoma
• Vascular leiomyosarcoma
• Immunocompromised host leiomyosarcoma
• Bone leiomyosarcoma

The exact cause of childhood leiomyosarcoma is not entirely understood, but studies suggest that genetics may play a role in the formation of all soft tissue sarcomas. In addition:

• There seems to be a link between leiomyosarcoma and Epstein-Barr virus infection.
• Children with AIDS and those who are undergoing immunosuppression therapy for solid organ transplantation are also at increased risk for developing leiomyosarcoma.
• Children with other forms of cancer, such as retinoblastoma, may be at higher risk for developing leiomyosarcoma as adults.

Because soft tissue sarcomas affect tissue that is elastic and easily moved, a tumor may exist for a long time before being discovered, growing large and pushing aside surrounding tissue. Symptoms vary greatly with the size, location, and spread of the tumor, but may include:

• Painless swelling or mass anywhere on the body.
• Pain or soreness caused by compressed nerves or muscles.
• Limping or other difficulty using the legs, feet, arms or hands.

How We Treat Childhood Leiomyosarcoma

Surgery to remove the tumor is the primary treatment for childhood leiomyosarcoma, sometimes followed by chemotherapy and radiation therapy to destroy any cancer cells that may have spread beyond the tumor, and to prevent a recurrence.

Please refer to childhood soft tissue sarcomas for additional information about diagnosis, treatment, and care that your child will receive from our experienced clinicians.