An extra-skeletal Ewing’s Sarcoma presenting with urinary retention- Impact of anatomical location on patient management; A case report

Background: Ewing’s sarcoma is one of the common malignant childhood tumours. The radiological features of pre-sacral Ewing’s sarcoma may mimic primary nerve sheath tumor or teratoma.

Case Presentation: A 16-year-old girl presented with acute retention of urine found to have a midline mass in the pre-sacral region of the pelvis in clinical examination and radiological scans. A preoperative biopsy was not done. The complex location and the need to excise the biopsy tract, if histology turned out to be malignant, predicated this decision. The tumor was entirely excised. The histological diagnosis was that of an Ewing’s Sarcoma, with focal infiltration of the surgical margins.

Conclusion: The anatomical site and size of an Ewing’s sarcoma should be considered before preoperative biopsy is considered. A biopsy result positive for malignancy would favor adjuvant chemotherapy and radiation, but requires the biopsy tract to be excised. Primary resection is the preferred choice when the location is complex.