.Neuroendocrine Tumors

Although pathologic concepts regarding squamous cell carcinoma and adenocarcinoma have remained relatively stable during the past 10 years, those regarding the class of neuroendocrine tumors have continued to undergo revision and refinement. Neuroendocrine tumors are defined as those that produce biogenic amines. Pathologically, this can be demonstrated by a positive argyrophil or argentaffin stain, the presence of neurorsecretory granules by electron microscopy.