Rhabdomyosarcoma

Rhabdomyosarcoma
Specialty	Oncology

A rhabdomyosarcoma is a type of cancer, specifically a sarcoma (cancer of connective tissues), in which the cancer cells are thought to arise from skeletal muscle progenitors. It can also be found attached to muscle tissue, wrapped around intestines, or anywhere, to include the neck area.

Presentation

Its two most common forms are embryonal rhabdomyosarcoma and alveolar rhabdomyosarcoma. In the former, which is more common in younger children, the cancer cells resemble those of a typical 6-to-8-week embryo. In the latter, which is more common in older children and teenagers, they resemble those of a typical 10-to-12-week embryo.

Epidemiology

Rhabdomyosarcoma is a relatively rare form of cancer.

It is most common in children ages one to five, and is also found in teens aged 15 to 19, although this is more rare. This cancer is also an adult cancer but it is rare.

St. Jude Children's Research Hospital reports that rhabdomyosarcoma is the most common soft tissue sarcoma in children. Soft tissue sarcomas make up 7 - 8% of childhood cancers.

Diagnosis

When rhabdomyosarcoma is suspected, tests will be run for blood, muscle, and marrow.

Diagnosis of rhabdomyosarcoma depends on recognition of differentiation toward skeletal muscle cells. The protein myo D1 is a protein normally found in developing skeletal muscle cells which disappears after the muscle matures and becomes innervated by a nerve. Thus, myo D1 is not found in normal skeletal muscle and serves as a useful immunohistochemical marker of rhabdomyosarcoma. Early manifestation can be misdiagnosed as a pseudotumor that is non responsive to steroid treatment.

Treatment

Treatment for rhabdomyosarcoma consists of chemotherapy, radiation therapy and sometimes surgery. Surgery to remove the tumor is often difficult or impossible because the tumor is usually embedded deep within the tissue, leaving it difficult to reach. If a tumor presents itself in the extremities, amputation is often necessary to improve chances of survival.

If there is no evidence of metastasis, surgery combined with chemotherapy and radiation offer the best prognosis. Patients whose tumors have metastasized usually have a poor chance for long-term survival. In patients who began treatment before metastasis, the prognosis is better, although the disease is generally incurable because the tumors that cannot be surgically removed tend to spread.

St Jude's Children's Research Hospital reports that more than 70% of children diagnoised with localized rhabdomyosarcoma have long-term survival.

Tungsten Alloy and RMS

Studies have shown a link between Tungsten alloy and RMS.

See also

• Rhabdomyoma
• Sarcoma botryoides

External links

• humpath #1956 (Pathology images)
• Ped-Onc Resource Center
• [http://www.liddyshriversarcomainitiative.org/Newsletters/V01N04/RMS/rms.htm
• [http://www.stjude.org/stjude/v/index.jsp?vgnextoid=64fb061585f70110VgnVCM1000001e0215acRCRD&vgnextchannel=bc4fbfe82e118010VgnVCM1000000e2015acRCRD&SearchUrl=search_results.jsp&QueryText=rhabdomyosarcoma}

Rhabdomyosarcoma by Leonard Wexler, MD]

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