RESUMEN
Primitive Neuroectodermal Tumor of the kidney is a rare entity. Very few cases of primary renal PNET have been reported to date. Most literature about rPNET is isolated case reports. We report a case of rPNET in a 39-year-old male with a pre-operative diagnosis of renal cell carcinoma with renal vein thrombosis. The patient underwent radical nephrectomy with thrombolectomy, and histopathological examination revealed a highly aggressive tumor composed of monotonous sheets of round cells. Tumor cells were positive for CD 99 and FLI-1, hence confirming the diagnosis of Primitive Neuroectodermal Tumor. Post-surgery, patient was given VAC/IE-based adjuvant chemotherapy. In view of highly aggressive nature of this tumor, prompt diagnosis and imparting effective chemotherapy regimen to the patient is required, and it is important to differentiate PNET from other small round-cell tumors because of different therapeutic approach.