Cancer that forms in the soft tissues in a type of muscle called striated muscle. Rhabdomyosarcoma can occur anywhere in the body.
Definition (NCI)
A malignant tumor showing skeletal muscle tumor differentiation and which does not show classic histologic features of described rhabdomyosarcoma subtypes (e.g. embryonal, alveolar). This term may be used for small biopsy specimens for which adequate tissue is not present for definitive classification.
Definition (MSH)
A malignant solid tumor arising from mesenchymal tissues which normally differentiate to form striated muscle. It can occur in a wide variety of sites. It is divided into four distinct types: pleomorphic, predominantly in male adults; alveolar (RHABDOMYOSARCOMA, ALVEOLAR), mainly in adolescents and young adults; embryonal (RHABDOMYOSARCOMA, EMBRYONAL), predominantly in infants and children; and botryoidal, also in young children. It is one of the most frequently occurring soft tissue sarcomas and the most common in children under 15. (From Dorland, 27th ed; Holland et al., Cancer Medicine, 3d ed, p2186; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, pp1647-9)
Definition (CSP)
highly malignant tumor of striated muscle derived from primitive mesenchymal cells and exhibiting differentiation along rhabdomyoblastic lines.
Definition (NCI)
A rare aggressive malignant mesenchymal neoplasm arising from skeletal muscle. It usually occurs in children and young adults. Only a small percentage of tumors arise in the skeletal muscle of the extremities. The majority arise in other anatomical sites.