Abstract

The advent of modern microscopical investigative methods for the determination of neuroendocrine differentiation has increasingly given credence to the original concept of a "diffuse endocrine system". These methods include a variety of silver impregnation techniques, technologically advanced light and electron microscopical immunocytochemistry, and, lately, the ability to localise specific binding sites by in vitro autoradiography and mRNA species by in situ hybridisation. Further insight has been gained into the possible role of regulatory peptides contained in the so called "diffuse endocrine system" and into the nature of disease processes by investigating the role of the system in benign and malignant disease.