Primary Mosaic Neuroendocrine-/Adenocarcinoma of The Prostate: Clinical and Histological Description

Abstract

Background: Mosaic cancers are composed of two or several genetically different cell populations. Mosaicism has been considered to be rare among malignancies, with the exception of the germ cell tumours. Although it has been described that neuroendocrine foci might be present within adenocarcinomas of the prostate, this was meant for advanced stage diseases and the clinical relevance of the histological finding has not been clarified. Patients and methods: We recall a single centre cohort of patients with neuroendocrine cancer of the prostate. We show for the first time histological images of a primary mosaic neuroendocrine/adenocarcinoma of the prostate. Results: Contrarily to the general assumption of a rare disease with poor prognosis, the clinical incidence was found to be 2%, being 50 fold higher than the earlier data. During the follow-up the overall survival of some metastatic patients reached several years. The particularity of patients with favourable outcome was the parallel elevation of PSA and NSE. They received anticancer treatments in an alternating way directed according to the tumour marker that was actually in rise. Histological images of primary mosaic prostate cancers are shown. A model explaining the development of mosaic cancers is presented. Conclusion: Mosaic neuroendocrine-/adenocarcinoma of the prostate is underdiagnosed and its prognosis is underestimated.