what is rms disease: RMS (Rhabdomyosarcoma) is a rare type of cancer that originates in the skeletal muscles or soft tissues of the body. It most commonly affects children and adolescents, and can present with a variety of symptoms depending on the location and stage of the tumor. Some common symptoms include swelling, pain, difficulty breathing, and unexplained weight loss. Early diagnosis and treatment are crucial for a favorable prognosis.