References
2. Tefft M, Vawter GF, Mitus A. Paravertebral "round cell" tumors in children. Radiology. 1969; 92:1501–1509.
3. Downing JR, Head DR, Parham DM, et al. Detection of the (11;22)(q24;q12) translocation of Ewing's sarcoma and peripheral neuroectodermal tumor by reverse transcription polymerase chain reaction. Am J Pathol. 1993; 143:1294–1300.
4. Raney RB, Asmar L, Newton WA Jr, et al. Ewing's sarcoma of soft tissues in childhood: a report from the Intergroup Rhabdomyosarcoma Study, 1972 to 1991. J Clin Oncol. 1997; 15:574–582.
5. Murtaza B, Saeed S, Khan NA, et al. Retroperitoneal masses: different clinical scenarios. J Ayub Med Coll Abbottabad. 2008; 20:161–164.
6. Kennedy JG, Eustace S, Caulfield R, Fennelly DJ, Hurson B, O'Rourke KS. Extraskeletal Ewing's sarcoma: a case report and review of the literature. Spine (Phila Pa 1976). 2000; 25:1996–1999.