Ewing's sarcoma is a PNET (Primitive Neuroectodermal Tumour) that develops in the diaphysis of a long bone. A child with Ewing's sarcoma is on radiotherapy and chemotherapy. Which of the following is a poor prognostic factor in Ewing's sarcoma?

Poor prognostic factors of Ewing's sarcoma: Fever Anemia Elevated serum lactate dehydrogenase (LDH) Pelvic primary tumor Large tumor volume The worse prognosis associated with pelvic Ewing's may be related to larger size of tumor compared with extremity lesions at diagnosis. Must know: Ewing's sarcoma typically involves the diaphyseal region of long bones. The presence of p30/32, 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 Ewing's sarcoma (and other members of the Ewing's family of tumors, sometimes called Primitive Neuroectodermal Tumors (PNETs). Glycogen-filled cytoplasm detected by staining with periodic acid-Schiff is also characteristic of Ewing's 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, t(11;22). Common sites of metastases are lungs, bones, and bone marrow. Ref: The Chemotherapy Source Book By Michael Clinton Perry, 4th edition, Page 480.