Ewing's sarcoma: A case report of a 52-year-old woman with recurrent tumor and literature review.

Ewing's sarcoma is the second most common primary sacral tumor. Ewing's sarcomas are rare, aggressive tumors with a tendency towards recurrence following resection and early metastasis. Although peak incidences are between the ages of 10 and 20 years, patients of younger or older age account for almost 30% of the cases. We report the case of a 52-year-old healthy female who presented with a 2-week history of pain in her right posterior thigh that was unable to be relieved by non-steroidal anti-inflammatory medicine and physical therapy. Magnetic resonance imaging demonstrated an irregular right presacral mass and core needle biopsy revealed a small, round blue cell neoplasm. Staging workup was normal and an open biopsy was positive for the ES translocation (22q12). The patient was treated with 17 cycles of vincristine, adriamycin and cytoxan with mesna rescue, alternating with ifosfamide and etoposide in addition to external beam radiation. Post-treatment imaging demonstrated complete resolution of the tumor. Six weeks post-treatment the patient presented with a recurrent tumor. This case emphasizes the importance of timely establishment of initial diagnosis, early metastasis in treatment responsive patients and under-utilization of positron emission tomography-computed tomography (PET-CT) during the treatment to detect sub-clinical metastasis.