Primary Ewing Sarcoma Within an Autosomal Dominant Polycystic Kidney: A Case Report

Introduction: Primary renal malignancies are one of the known complications in individuals with inherited cystic kidney disease. This report describes the first documented case of primary Ewing sarcoma arising within an autosomal dominant polycystic kidney. Case Description: A 44-year-old male with end-stage renal disease secondary to autosomal dominant polycystic kidney disease presented with left flank pain and peritoneal dialysis catheter dysfunction due to clotting. Imaging revealed a 14 cm heterogeneous mass in the lower pole of the left kidney (Figure 1a,b). The patient underwent laparoscopic left nephrectomy, and pathology examination confirmed the diagnosis of primary Ewing sarcoma (Figure 1c,d). He received 12 cycles of adjuvant chemotherapy, including vincristine, dactinomycin, and cyclophosphamide. Despite this, disease relapse occurred 13 months after the initial diagnosis (Figure 1e,f). Discussion: Primary Ewing sarcoma of the kidney is an exceptionally rare malignancy with nonspecific clinical and imaging features. Its rarity complicates the development of standardized treatment approaches, and it is associated with a poor prognosis due to delayed diagnosis, high metastatic potential, and frequent recurrence.