Unveiling the Uncommon: A Case of Metastatic Ewing Sarcoma of the Kidney.

Primary Ewing sarcoma of the kidney (ESK) is a rare and aggressive entity, with a poor prognosis. It often presents as metastatic disease with the lungs being the most common site. In adults, the occurrence of these tumors is uncommon, with patients exhibiting non-specific symptoms such as weight loss, flank pain, hematuria, and an abdominal mass. The combination of these vague clinical symptoms and the rarity of these tumors often results in a delayed diagnosis, leading to poorer outcomes for these patients. We present a case of a 38-year-old female with metastatic ESK. The patient initially presented with abdominal pain, vomiting, and a four-day history of constipation. The diagnosis was confirmed through computed tomography scans, ultrasound-guided biopsy of the lesion, and fluorescence in situ hybridization that revealed translocation of the EWS gene on chromosome 22q12. She was managed with chemotherapy regimens and palliative care; however, the disease progressed and she passed away six months after her initial diagnosis.