Relation between WHO Classification and Location- and Functionality-Based Classifications of Neuroendocrine Neoplasms of the Digestive Tract

Neuroendocrinology, vol. 114, pp. 120–133

Abstract

Practice of neuroendocrine neoplasms (NENs) of the digestive tract, which comprise of a highly diverse group of tumors with a rising incidence, faces multiple biological, diagnostic, and therapeutic issues. Part of these issues is due to misuse and misinterpretation of the classification and terminology of NENs of the digestive tract, which make it increasingly challenging to evaluate and compare the literature. For instance, grade 3 neuroendocrine tumors (NETs) are frequently referred to as neuroendocrine carcinomas (NECs) and vice versa, while NECs are, by definition, high grade and therefore constitute a separate entity from NETs. Moreover, the term NET is regularly misused to describe NENs in general, and NETs are frequently referred to as benign, while they should always be considered malignancies as they do have metastatic potential. To prevent misconceptions in future NEN-related research, we reviewed the most recent terminology used to classify NENs of the digestive tract and created an overview that combines the classification of these NENs according to the World Health Organization (WHO) with location- and functionality-based classifications. This overview may help clinicians and researchers in understanding the current literature and could serve as a guide in the clinic as well as for writing future studies on NENs of the digestive tract. In this way, we aim for the universal use of terminology, thereby providing an efficient foundation for future NEN-related research.

Authors 5

1. Noah C. Helderman Aachen Department of Clinical Genetics

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands

   Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands;

2. Manon Suerink Aachen Department of Clinical Genetics

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands

   Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands;

3. José G. van den Berg

   The Netherlands Cancer Institute

   Affiliation as printed

   Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands

   Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands;

4. Maartje Nielsen Aachen Department of Clinical Genetics

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands

   Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands;

5. Margot E. T. Tesselaar

   The Netherlands Cancer Institute

   Affiliation as printed

   Department of Gastrointestinal Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands

   Department of Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands

   Department of Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands;