Practical markers used in the diagnosis of neuroendocrine tumors.

Although there are many broad-spectrum neuroendocrine markers, chromogranin and synaptophysin are the principal ones used in diagnostic pathology. Other broad-spectrum neuroendocrine markers, transcription factors, and specific peptide markers used in the diagnosis of neuroendocrine tumors are reviewed. The use of different keratins in the differential diagnosis of endocrine tumors is also presented. The importance of using low-molecular-weight keratins such as CAM5.2 to avoid false-negative results in the workup of some neuroendocrine tumors is emphasized. Finally, the use of in situ hybridization in diagnostic pathology is briefly summarized.