Rhabdomyosarcoma is a type of cancer that forms in muscles attached to bone, most commonly affecting children. It can occur in different parts of the body, with symptoms varying depending on the location. Treatment is very aggressive, typically involving chemotherapy, radiation, and surgery, with the goal of beginning treatment immediately given the cancer's ability to spread before detection. The document focuses on a 5-year-old boy named Dorian who was diagnosed with Stage 4 Alveolar Rhabdomyosarcoma in his leg and has since completed treatment, serving as an example of the impact of this type of cancer on children.