Neuroendocrine differentiation in prostatic carcinomas: Histogenesis, biology, clinical relevance, and future therapeutical perspectives

Since the introduction of immunohistochemistry, there is an increasing inte rest in neuroendocrine (NE) differentiation in prostatic carcinomas. Focal NE-differentiation in prostatic adenocarcinomas is a very frequent finding. It is subject of numerous studies, since a negative impact on prognosis an d an important role in antiandrogen therapy failure are suspected. NE-diffe rentiated small-cell carcinoma is a very rare tumor comprising 0.5-2% of al l prostatic carcinomas. Nevertheless, although very rare, it is of clinical importance because it is one of the most aggressive turners of the prostat e with a very poor prognosis. This review is focused on actual concepts of histogenesis, cell biology, clinical implications, and possible future ther apeutic perspectives of these two tumor entities.