Partial nephrectomy for incidental primary renal neuroendocrine carcinoma: case report.

Here we present an 83-year-old woman who was referred to our hospital and had had left flank pain and oligouria for 3 days. Plain abdominal film and ultrasonography revealed left ureteropelvic junction stone with obstructive uropathy. The serum level of creatinine fell to 3.1 mg/dl from 7.6 mg/dl after ureteral catheter drainage was given 5 days after admission. Then a left pyelolithotomy was performed and a tumor of 2 x 1 x 1 cm over the lower pole of the left kidney was found incidentally. Partial nephrectomy was performed in consideration of her age and poor renal function although the biopsy result showed it to be carcinoma. The final pathological report and immunohistochemical study results proved that it was neuroendocrine carcinoma. To our knowledge, this is the first case of primary renal neuroendocrine carcinoma to be treated using conservative surgery. The clinical course was acceptable, since she had been found to be free of disease during regular follow-up of 2.5 years with the creatinine level of about 2.5 mg/dl.