Neuroendocrine differentiation of prostatic adenocarcinoma - An important cause for castration-resistant disease recurrence

Abstract

Neuroendocrine differentiation of prostatic carcinoma is a rare entity associated with metastatic castration-resistant disease. Among useful biomarkers of neuroendocrine differentiation, chromogranin A, serotonin, synaptophysin and neuron-specific enolase stand out, while total prostate-specific antigen (PSA) levels are often low or undetectable. We report a case of prostatic adenocarcinoma recurrence after a 6-year disease-free follow-up, in which increased serum chromogranin A levels and undetectable total PSA provided a prompt indication of neuroendocrine transformation, confirmed through immunohistochemical evaluation. Neuroendocrine differentiation is a relevant cause of prostatic adenocarcinoma recurrence, and awareness of this entity is crucial due to its underdiagnosis and adverse prognosis.