Definition:

Rhabdomyosarcomas (RMSs) are soft tissue sarcomas that are one of the most common neoplasms in children and adolescents. RMSs are presumed to be associated with the skeletal muscle lineage, although those tumors can be present in organs histologically lacking skeletal muscle, like prostate, urinary bladder or gallbladder. RMS comprises a heterogeneous into two major histologic subtypes, embryonal (ERMS) and alveolar (ARMS). Alveolar rhabdomyosarcoma (ARMS) is a pediatric sarcoma that typically occurs in older children predominantly arising in the trunk and extremities, and exhibits a worse prognosis than other types of RMSs. ARMS is associated with 2;13 or 1;13 chromosomal translocations, which generate PAX3-FOXO1A and PAX7-FOXO1A fusion products, respectively. These translocations result in altered expression, function, and subcellular localization of the fusion products relative to the wild-type proteins, and ultimately contribute to oncogenic behavior by modifying growth, differentiation, and apoptosis pathways.