<prompt> Ewings sarcoma is a PNET Primitive Neuroectodermal Tumour that develops in the diaphysis of a long bone. A child with Ewings sarcoma is on radiotherapy and chemotherapy. Which of the following is a poor prognostic factor in Ewings sarcoma?Increased levels of B2-globulinFeverThrombocytosisYounger age  <response>: Poor prognostic factors of Ewings sarcoma: Fever Anemia Elevated serum lactate dehydrogenase LDH Pelvic primary tumor Large tumor volume The worse prognosis associated with pelvic Ewings may be related to larger size of tumor compared with extremity lesions at diagnosis. Must know: Ewings sarcoma typically involves the diaphyseal region of long bones. The presence of p3032, the product of the mic-2 gene which maps to the pseudoautosomal region of the X and Y chromosomes is a cell-surface marker for Ewings sarcoma and other members of the Ewings family of tumors, sometimes called Primitive Neuroectodermal Tumors PNETs. Glycogen-filled cytoplasm detected by staining with periodic acid-Schiff is also characteristic of Ewings sarcoma cells. The classic cytogenetic abnormality associated with this disease and other PNETs is a reciprocal translocation of the long arms of chromosomes 11 and 22, t11;22. Common sites of metastases are lungs, bones, and bone marrow. Ref: The Chemotherapy Source Book By Michael Clinton Perry, 4th edition, Page 480. 