Sarcomas are malignant tumors that arise from mesenchymal tissue at any site in the body. These tissues have the potential to differentiate into striated muscle, smooth muscle, adipose tissue, fibrous tissue, bone, or cartilage. Rhabdomyosarcomas are derived from immature cells that would develop into striated skeletal muscle. Rhabdomyosarcomas vary by site and are the most common soft tissue tumor of childhood.

Sarcoma botryoides is a variant of the embryonal type of rhabdomyosarcomas that are classified histologically by rhabdomyoblasts. These masses can arise from the bladder, prostate, and male or female genital tracts. It is mostly seen as a vaginal tumor in infants but can also be seen as a cervical tumor during reproductive years and in the body of the uterus during the postmenopausal stage.

Risk factors are not known for many childhood cancers. Epidemiologic studies have shown associations of rhabdomyosarcomas with radiation exposure in utero, low socioeconomic status, those who received antibiotics soon after birth, and recreational drug use during pregnancy. Many of these cancers are sporadic but can occasionally be associated with pathogenic variants.