Neuroendocrine Tumours Flashcards
What are neuroendocrine cells?
Cells that receive input from neurotransmitters to release hormones into the blood stream.
This allows communication between nervous system and endocrine systems.
What neuroendocrine tumours can be found in the tubular GI tract and pancreas?
Gastroenteropancreatic Neuroendocrine tumours (GEP-NETs)
They all have malignant potential
Where are most GEP-NETs found?
In the small intestine
Rest are in rectum or in the stomach
Grading classification of GEP-NETs
Grade 1 - Well differentiated, mitotic count <2 per 10 HPF, KI index <3%
Grade 2 - Well differentiated, mitotic count 2-20 per 10 HPF, KI index 3-20%
Grade 3 - Poorly differentiated, mitotic count >20 per 10HPF, KI index >20%
Risk factors
Genetic
Multiple Endocrine Neoplasia Type 1 (MEN1)
Von Hippel-Lindau disease (VHL)
Neurofibromatosis (NF-1)
Tuberous sclerosis complex (TSC)
Clinical features
Often non-specific symptoms like vague abdo pain, N+V
Abdo distension
Can have bowel obstruction
Unintentional weight loss
Palpable abdo mass
Also assess for underlying inherited disorder.
How can GEP-NETs be classified?
Funcitioning or non-functioning depending on evidence of hormonal hypersecretion.
Majority are non-functioning.
What can well-differentiated midgut NETs present as?
Carcinoid syndrome
Explain carcinoid syndrome
Well-differentiated GEP-NETs can spread and lead to carcinoid syndrome developing.
It occurs following metastasis of a carcinoid tmour.
The metastis will start secreting mediators like serotonin, prostaglandin or gastrin e.g.
This can lead to flushing, abdo pain, diarrhoea, wheezing or palpitations.
Laboratory tests for GEP-NET
Chromogranin A
5-HIAA levels
FBC + LFTs and other routine bloods.
Chromogranin B and pancreatic peptide might be useful as well.
Genetic testing can also be done if clinical history suggests it.
Specialised tests if bloods are suggestive of GEP-NET
Depending on the location endoscopy should be used.
CT enteroclysis is the imaging of choice in case it is a small bowel NET
Metastatic disease warrants whole body somatostatin receptor scintigraphy (SSRS)
Management
Surgery is the only curative treatment
Metastatic disease is a common presentation which means that any surgical treatment would only be palliative.
Management of poorly differentiated GEP-NETs
Poor prognosis but if the disease is localised surgical resection -> chemotherapy can be done.
In metastatic dsiease palliative chemo alone is advised
Management of well-differentiated GEP-NETs
Managed according to site, staging and functionality.
Localised -> resected
Liver metastases can also be resected along with the primary tumour
Surgical management of gastric NETs
Depends on subtype.
Type 1 and Type 2 have low metastatic potential -> endoscopic resection + annual surveillance.
Type 3 -> Aggressive lesions which requires partial or total gastrectomy with lymph node clearance.
