[Renal neuroendocrine tumor (carcinoid) : a case report].

A 32-year-old man was referred to our hospital for treatment of left renal cystic tumor, which was detected by computed tomographic (CT) scan 3 years ago. CT scan showed a multilocular cyst (5 cm in diameter) with a solid tumor in the left kidney which was enhanced with contrast. There was no evidence of extrarenal invasion or distant metastasis. We performed retroperitoneal laparoscopic radical nephrectomy. Pathological examinations revealed a cellular arrangement specific to carcinoid tumor and positive for CD56 (NCAM) and neuron-specific enolase. The cell proliferation rate was estimated to be under 2% with Ki67 staining. The pathological diagnosis was renal neuroendocrine tumor (carcinoid). At the 9-month follow up, he had no evidence of local recurrence or metastasis.