Divergent neuroendocrine differentiation in prostatic carcinoma.

A rich variety of neuroendocrine cells are present in the normal prostate gland. Prostatic carcinoma may show divergent differentiation towards a neuroendocrine phenotype in the form of neuroendocrine small cell carcinoma or carcinoid-like tumors. Much more common is focal neuroendocrine differentiation in prostatic adenocarcinoma which may be pronounced in approximately 10% of adenocarcinomas. The prognostic significance of focal neuroendocrine differentiation in prostatic carcinoma is controversial but current evidence suggests an influence on prognosis related to hormone resistant tumors and/or a role in the conversion to a hormonal resistant phenotype. Chromogranin A appears to be the best overall tissue and serum marker of neuroendocrine differentiation. Chromogranin A serum levels may be useful in the assessment of the emergence of and/or progression of hormone resistant cancer.