Ewing's sarcoma and extracranial peripheral neuroectodermal tumors.

Ewing's sarcoma and extracranial primitive neuroectodermal tumors of bone and soft tissue are small round-cell tumors that comprise a family of neoplasms distinguished by a cytogenetic marker that can be detected by reverse transcription and polymerase chain reaction. Based on molecular and immunohistochemical studies, it is generally acknowledged that this is a family of neuroectodermal tumors. Molecular methods allow accurate diagnosis with minimally invasive surgical options, provide a manner to detect minimal residual disease, and begin to shed light on the pathogenesis of these entities. Combined modality treatment regimens continue to improve the outlook for nonmetastatic Ewing's sarcoma and primitive neuroectodermal tumors patients. Patients who present with metastatic disease may benefit from intensive therapy as facilitated by peripheral stem cell and autologous bone marrow rescue programs.