Source:http://linkedlifedata.com/resource/umls/id/C0585474
NCI: A small round cell tumor that lacks morphologic, immunohistochemical, and electron microscopic evidence of neuroectodermal differentiation. It represents one of the two ends of the spectrum called Ewing sarcoma/peripheral neuroectodermal tumor. It often affects the diaphysis or metaphyseal-diaphyseal portion of long bones. Clinical findings include pain and a mass in the involved area. Fever, anemia, leucocytosis, and an increased sedimentation rate are often seen. X-ray examination reveals osteolytic lesions. The prognosis depends on the stage, anatomic location, and size of the tumor. -- 2003