Learning objectives
We aim to discuss and illustrate examples of both the typical and atypical cases of GI-NETs encountered in our institution using cases as examples
After reading this presentation,
you should be able to recognise the typical imaging features of GI-NETs and be able to apply this knowledge to differentiate GI-NETs from other neoplasms
Background
What are NETs?
Neuroendocrine tumours of the gastrointestinal tract (GI-NETs) comprise a genetically diverse spectrum of malignant neoplasms arising from the secretory cells of the neuroendocrine system.
The involved secretory cells produce peptides which may cause characteristic hormonal syndromes in some patients
Where do we find them?
GI-NETs are most commonly found in the pancreas
Certain subtypes arise elsewhere;
Gastrinomas primarily affect the pancreas but can also arise in the duodenum,
lymph nodes and adrenal glands
Vasoactive polypeptide secreting tumours (VIPomas) are primarily pancreatic in...
Findings and procedure details
Imaging Features:
Classical imaging features of GI-NETs:
Well-circumscribed round or oval in shape
Hypoechoic echotexture on ultrasound
Conversely neuroendocrine liver metastases are typically hyperechoic on ultrasound
GI-NETs are homogenously hypervascular tumours and their appearance on computed tomography (CT) follows a pattern of low attenuation on non-contrast studies to hyperattenuation on late arterial phase imaging with decreased enhancement on portal venous and delayed phase studies
Magnetic Resonance Imaging offers superior intrinsic soft-tissue contrast. Most GI-NETs demonstrate low signal on T1-weighted imaging and high signal intensity on...
Conclusion
GI-NETs are an important differential diagnosis to consider for masses in the pancreas,
small bowel,
stomach,
biliary tree and lymph nodes
This educational exhibit serves to educate the observer on their typical and atypical imaging features by providing a comprehensive discussion including unusual cases from our institution
References
Annals of Oncology,
Volume 21,
Issue suppl_7,
1 October 2010
The Lancet,
Oncology, Volume 9,
Issue 1,January 2008,
Pages 61-72
European Neuroendocrine Tumour Society