Etiology • Unknown • Chromosomal translocations t(11;22), t(7;22), t(7;21) noted • Gene rearrangement often noted, that is, (22;q12) and expres-
sion of the MIC2 gene • Genetically related to primitive peripheral neuroectodermal
tumor via translocations t(11;22), (q24;q12)
sion of the MIC2 gene • Genetically related to primitive peripheral neuroectodermal
tumor via translocations t(11;22), (q24;q12)
Clinical Presentation • 60% in males; over 95% in those under 20 years of age • Chiefly in bone and soft tissues • Highly malignant • Pain, numbness, and swelling often early complaints • Diffuse, irregular, lytic bone lesion • Cortical expansion variable • Second most common bone tumor of children/adolescents • Soft tissues of head and neck account for 11% of extraskeletal
sites
Diagnosis • Radiographs often show “moth-eaten” appearance and lami-
nar periosteal bone reaction • Cortex may be eroded or expanded
Differential Diagnosis • Osteosarcoma • Lymphoma • Peripheral neuroectodermal tumor of bone • Primitive rhabdomyosarcoma • Neuroectodermal tumor of infancy
sites
Diagnosis • Radiographs often show “moth-eaten” appearance and lami-
nar periosteal bone reaction • Cortex may be eroded or expanded
Differential Diagnosis • Osteosarcoma • Lymphoma • Peripheral neuroectodermal tumor of bone • Primitive rhabdomyosarcoma • Neuroectodermal tumor of infancy
Treatment • Radiation and multiagent chemotherapy
Prognosis • 54 to 74% 5-year survival rate in localized osseous form • Late relapse not uncommon
Prognosis • 54 to 74% 5-year survival rate in localized osseous form • Late relapse not uncommon