Home > G. Tumoral pathology > neuroendocrine tumors
neuroendocrine tumors
Monday 28 June 2004
NET; NETs
| WKP |
Definition: Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. Many are benign, while some are malignant. They most commonly occur in the intestine, but they are also found in the pancreas, lung and the rest of the body.
Benign neuroendocrine tumors (NETs), previously called "carcinoid tumors", are neoplasms of enterochromaffin/neuroendocrine cell origin which display neurosecretory capacity that may result in the carcinoid syndrome.
The annual incidence of patients with NET is 8.4 per 100000; yet many NET remain asymptomatic and clinically undetected. A majority of NET follows a benign course; however, some will display malignant characteristics.
NET most commonly occur in the gastrointestinal tract (67%) and bronchopulmonary system (25%). Gastrointestinal NET occur within the stomach, small intestine, liver, and rectum.
Classification
The World Health Organization (WHO) classification scheme places neuroendocrine tumors into three main categories, which emphasize the tumor grade rather than the anatomical origin:
well-differentiated neuroendocrine tumors, further subdivided into tumors with benign ("typical carcinoid tumor") and those with uncertain behavior ("atypical carcinoid tumor")
well-differentiated (low grade) neuroendocrine carcinomas with low-grade malignant behavior
poorly differentiated (high grade) neuroendocrine carcinomas, which are :
- large cell neuroendocrine carcinoma
- small cell neuroendocrine carcinoma.
Images
Old WHO 2010 compared to the new WHO 2017 grading of neuroendocrine tumours (NETS) from new WHO blue book.
Digital cases
JRC:481 : High-grade neuroendocrine carcinoma (possibly anaplastic medullary carcinoma)
JRC:1591 : Spindle cell carcinoid tumor of the lung
Classification
thyroid medullary carcinoma
neuroendocrine carcinoma
paraganglioma
parathyroid adenoma
carcinoid tumor
- bronchial carcinoid tumor
- duodenal carcinoid tumor
- ileal carcinoid tumor
- appendiceal carcinoid tumor
Localization
pancreatic neuroendocrine tumors
digestive neuroendocrine tumors
thyroid neuroendocrine tumors
pulmonary neuroendocrine tumors
Subtypes
multifocal neuroendocrine tumors
Grading
Grading with Ki-67 (22895268)
Genetics
11q LOH (21%) (15920555)
16q (13%) (15920555)
18 (30%) (15920555)
BRAF locus
See also
neuroendocrine organs
neuroendocrine markers
Paywall References
Algorithmic approach to neuroendocrine tumors in targeted biopsies: Practical applications of immunohistochemical markers. 2018. PMID: 27529763 doi : 10.1002/cncy.21765
Paywall References
Grading of Neuroendocrine Tumors With Ki-67 Requires High-quality Assessment Practices. Remes SM, Tuominen VJ, Helin H, Isola J, Arola J. Am J Surg Pathol. 2012 Sep;36(9):1359-63. PMID: 22895268
Chung DC. Cyclin D1 in human neuroendocrine tumorigenesis. Ann N Y Acad Sci. 2004 Apr;1014:209-17. PMID: 15153436
