The Colorful Palette of Neuroendocrine Neoplasms in the Genitourinary Tract

BACKGROUND: Neuroendocrine neoplasms include a heterogeneous group of malignant tumors. Primary neuroendocrine tumors in the genitourinary tract are rare, comprising approximately 1-2% of genitourinary malignancies. MATERIALS AND METHODS: An extensive search was performed for publications between 2000 and 2018 regarding neuroendocrine tumors of the genitourinary tract. Epidemiological, clinical, histopathological, prognostic and therapeutic data were evaluated. RESULTS: Neuroendocrine tumors of the kidneys are exceedingly rare, mostly well-differentiated. 0.5-1% of all primary bladder malignancies are small cell neuroendocrine carcinomas. Characteristically, prostatic adenocarcinoma with neuroendocrine differentiation occurs in androgen receptor-independent/castrate-resistant cancer. Small cell and large cell neuroendocrine carcinomas are the most aggressive tumors in each location. CONCLUSION: Due to the rarity and poor prognosis of these tumors, proper pathological diagnosis and early therapy are important. Therapeutic guidelines are not available. Surgery, radiotherapy and/or chemotherapy are possible treatment options; somatostatin analogs are used as standard therapy in case of well-differentiated neuroendocrine tumors.