Types of rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a cancerous tumour of the muscle cells that can grow into nearby tissue and destroy it. The tumour can also spread (metastasize) to other parts of the body. Cancerous tumours are also called malignant tumours. There are 2 main types of RMS.

Embryonal RMS is the most common type of RMS in children. It makes up about 50% to 70% of all rhabdomyosarcomas in children. It is more common in younger children and most commonly found in children under the age of 10 years.

Embryonal RMS can happen anywhere in the body but usually develops in the head and neck and in the organs of the reproductive system and urinary system.

Alveolar RMS develops more often in older children and teens. About 20% of all RMS in children are alveolar. It can happen anywhere in the body but usually develops in the muscles of the arms and legs and the muscles of the chest and abdomen.

The following are rare types of RMS.

Undifferentiated sarcoma is a type of sarcoma where the cells don't look like a specific type of soft tissue sarcoma. Doctors may group undifferentiated sarcomas with RMS.

Pleomorphic RMS is usually diagnosed in adults and is hard to treat. It is not usually found in children. Pleomorphic RMS may also be called anaplastic RMS.