Clinical Considerations and Prognosis of Well-Differentiated Neuroendocrine Tumor Occurring Within a Renal Teratoma-A Case Series

center dot The preoperative diagnosis of well-differentiated neuroendocrine tumor within a renal teratoma has remained challenging because no imaging modality or laboratory test has been shown to reliably determine whether a known endocrinologically quiescent renal mass contains elements of neuroendocrine tumor. center dot Complete surgical resection has been the primary treatment modality for all known cases of neuroen-docrine tumor within a renal teratoma, and it appears to be curative for localized disease. center dot Radical nephrectomy and partial nephrectomy have resulted in comparative outcomes. center dot Postoperative monitoring with serum 5-hydroxyindole acetic acid levels, computed tomography, magnetic resonance imaging, and/or octreotide scans has been proposed; however, the clinical utility of these tests in detecting recurrence remains unclear. center dot Based on available case reports, the overall prognosis of well-differentiated neuroendocrine tumor within a renal teratoma appears favorable. No case reports have described metastasis at diagnosis or within the available follow-up periods. This differs from primary renal neuroendocrine tumor, because nearly one half of these patients will be found to have metastatic disease at the initial diagnosis.