Neuroendocrine System
The neuroendocrine system is composed of specialized cells, which combine the properties of neuronal cells that respond to neural stimuli as well as endocrine cells that synthesize and excrete hormones, amines or peptides into the bloodstream (Asa, Rosa, and Mete. 2020). In addition, these cells express specific protein markers such as synaptophysin in the membranes of intra-cytoplasmic small presynaptic-like vesicles or chromogranin A in large dense core hormone granules (Klöppel G. 2017) (Figure 1).
Neuroendocrine cells are distributed throughout the body, including:
glands such as the pituitary, parathyroids and adrenals
clusters within glands, such as islet cells in the pancreas secreting insulin and C cells in the thyroid secreting calcitonin
scattered within the exocrine parenchyma, particularly in the gastrointestinal (GI) and respiratory tracts (Oronsky B et al. 2017)
References:
Asa, Sylvia L., Stefano La Rosa, and Ozgur Mete. 2020. The Spectrum of Neuroendocrine Neoplasia: A Practical Approach to Diagnosis, Classification and Therapy. Springer Nature. DOI: https://doi.org/10.1007/978-3-030-54391-4
Klöppel, Günter. 2017. “Neuroendocrine Neoplasms: Dichotomy, Origin and Classifications.” Visceral Medicine 33(5): 324–30. DOI: 10.1159/000481390
Waldum, Helge L. et al. 2018. “Not Only Stem Cells, but Also Mature Cells, Particularly Neuroendocrine Cells, May Develop into Tumours: Time for a Paradigm Shift.” Therapeutic Advances in Gastroenterology 11: 1756284818775054. DOI: 10.1177/1756284818775054
Oronsky, Bryan, Patrick C. Ma, Daniel Morgensztern, and Corey A. Carter. 2017. “Nothing But NET: A Review of Neuroendocrine Tumors and Carcinomas.” Neoplasia 19(12): 991–1002. DOI: 10.1016/j.neo.2017.09.002
