Primitive neuroectodermal tumor of the kidney with inferior vena cava tumor thrombus.

Primitive neuroectodermal tumor (PNET) of the kidney is an extremely rare disease with high aggressive tendency, considered to have a poor prognosis. We report the case of a 41-year-old man with a PNET arising from the kidney with inferior vena cava thrombus. This case was presumptively diagnosed of renal cell carcinoma prior to surgery. The diagnosis of PNET was made on the basis of findings of histopathology and immunohistochemistry. Postoperative computed tomography demonstrated residual disease. Subsequently, multidrug chemotherapy and radiotherapy were administrated. The patient is still alive with no evidence of disease 9 months after initial diagnosis. This presentation of a PNET is noteworthy because of its unusual location, the kidney being an extraordinary rare site for the tumor.