Histopathologic classification of neuroendocrine neoplasms A recently proposed aommon classification framework
Histopathologic classification of neuroendocrine neoplasms
A recently proposed aommon classification framework
Maryam Tohidi
Associate professor of anatomical & clinical pathology
Research Institute for Endocrine Sciences
Shahid Beheshti University of Medical Sciences
November 2018
Tehran, Iran
Introduction
- Neuroendocrine neoplasia (NEN) is an obscure family of tumors originating from epithelial or non-epithelial neoplasm with predominant neuroendocrine differentiation.
- Neuroendocrine- programmed cells are:
- Widely distributed in the body
- From different embryologic origin
Neuroendocrine-programmed cells
- Certain organs entirely composed of neuroendocrine cells:
- Neuroendocrine cells as microscopically identifiable aggregates in non-neuroendocrine organs:
Neuroendocrine-programmed cells
- Neuroendocrine cells diffusely dispersed in the epithelium of:
- Endodermal derived organs
- Ectodermal-derived structures
(neuronal structures, Merkel cells of skin)
- Mesodermal-derived structures (urogenital ridge)
Neuroendocrine neoplasms (NENs)
- NENs arise at almost any anatomical site
- NENs share major morphological and protein expression signatures depending on differentiation.
- NENs express a variable spectrum of proteins, shared with their normal cell of origin at specific anatomical locations
- Markers of general neuroendocrine differentiation
such as chromogranin A, chromogranin B, and synaptophysin
-
- Site-specific markers such as hormones and transcription factors
