BACKGROUNDPrimary Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) of urogenital tract is a rare condition with non-specific clinical presentations, which can make it difficult to diagnose. In this study, we summarize the clinical presentation, pathological features, therapeutic strategies, and prognosis of ES/PNET.

METHODSClinical information on two cases of ES/PNET in the penis and ureter was analyzed, and relevant literature was reviewed.

RESULTSES/PNET was confirmed pathologically, immunohistochemically and via molecular biology techniques in the penis (n=1) and ureter (n=1). In one case, a tumor was found at the base of penis, which had invaded the corpus cavernosum, and resulted in a massive enlargement of the penis. This tumor was initially diagnosed as an endocrine disorder. However, a confirmed diagnosis was made 11 months later when massive metastases in both lungs were noted. A tumor biopsy was performed to confirm the diagnosis, and chemotherapy with a CAV (cyclophosphamide+doxorubicin+vincristine)+IE (ifosfamide+etoposide) regimen for 9 months was prescribed. In the second case, a child was admitted due to abdominal pain and a hydroureter in the right kidney, as determined by ultrasonography. A tumor was found in the right ureter at the level of iliac vessels. Removal of the tumor and ureteral anastomosis were performed, and chemotherapy with CAV+IE for 8 months were prescribed. Both patients are currently being followed-up closely.

CONCLUSIONSES/PNET is a highly malignant tumor and has poor prognosis. Pre-operative diagnosis of ES/PNET of urogenital tract is difficult and largely depends on pathology, immunohistochemistry, and, if applicable, molecular biology. Comprehensive therapy may include surgery, chemotherapy and radiotherapy.