RHABDOMYOSARCOMA - CHILD

Rhabdomyosarcoma (RMS) accounts for approximately 3.5 percent of cancers among children 0 to 14 years and 2 percent of the cases among adolescents and young adults 15 to 19 years of age. Thus in total there are only about 500 to 800 children afflicted with RMS per year in the US.

The existing body of medical literature and research into pediatric RMS is not large. Furthermore, there are numerous complexities involved in the diagnosis and treatment of patients with RMS. It is thus advisable that children with rhabdomyosarcoma be treated at major medical centers, where the medical staff is familiar with the disease. 

Rhabdomyosarcoma is considered a curable disease if the child receives the best possible treatment. More than 60 percent of affected children survive five years after diagnosis.

Rhabdomyosarcoma is a malignant tumor of what is called 'striated' muscle - that is, muscle that is largely or totally under voluntary control, as opposed to so-called smooth muscle, which is the involuntary kind of muscle that is found in the walls of blood vessels and internal organs such as the stomach and intestines. Striated muscle arises during embryonic development from the primitive structure known as the mesenchyme, and any organ or tissue that retains elements of the embryonic mesenchyme can, theoretically, give rise in childhood or later life to a rhabdomyosarcoma.

There are four major histologic (tissue type) categories of RMS: embryonal, botryoid, alveolar and pleomorphic.  

Of all the solid cancers of children, sarcomas are the most common. And of all the soft tissue sarcomas, rhabdomyosarcoma of muscle is the most common type. The most common site is the head and neck, followed by the genito-urinary area, e.g. the bladder, the vagina in girls and the prostate in boys. The trunk, chest, back and abdomen muscles are less commonly involved. There are other possible primary sites for this disease including the intrathoracic (chest) region, the gastrointestinal tract (including liver and biliary tract), and the perineal/anal regions - all places where mesenchymal remnants are commonly found. There are also cases of rhabdomyosarcoma that arise in the paranasal sinuses. Another uncommon subgroup of rhabdomyosarcoma is parameningeal cancer, occurring within the central nervous system, or CNS.