Neuroendocrine tumours - general Flashcards
(23 cards)
What are NETs?
A heterogeneous group of neoplasms originating from neuroendocrine cells, classified by their embryological origin into foregut, midgut, and hindgut tumours.
NET is preferred over the term carcinoid.
What are the commonest sites of NET?
- Appendix (35%)
- Ileum (15%)
- Rectum (10%)
- Lung (15%)
What are the clinical features of NET?
Can be asymptomatic or present with obstructive symptoms like pain, nausea, and vomiting. Secretory tumours may cause carcinoid syndrome characterized by flushing, diarrhoea, and palpitations.
Carcinoid crisis includes profound flushing, bronchospasm, and tachycardia.
What is carcinoid syndrome?
A condition resulting from metastases to the liver, leading to the release of hormones into systemic circulation, characterized by flushing, diarrhoea, and palpitations.
What is the genetic background of NET?
NETs may occur as part of familial endocrine cancer syndromes like MEN1 and MEN2, but most are sporadic. Family history and clinical examination are important for diagnosis.
What baseline tests are recommended for suspected NET?
- Chromogranin A (CgA)
- 5-Hydroxy indole acetic acid (5-HIAA)
What is the gold standard for diagnosing NET?
Detailed histology.
What imaging modalities are used for NET?
- CT scan
- Endoscopy
- Somatostatin receptor scan (SSRS)
What is the sensitivity of SSRS for gut NETs?
90%.
How are NETs classified according to the WHO classification?
- Well differentiated endocrine tumour of probable benign behaviour
- Well differentiated endocrine tumour of uncertain behaviour
- Well differentiated endocrine carcinoma
- Poorly differentiated endocrine carcinoma
What is the primary aim of NET treatment?
Curative where possible, but often palliative in cases of metastatic disease.
What is the role of surgery in NET treatment?
Only curative treatment; indicated for primary tumours based on size and location.
What is the recommended follow-up for incidental carcinoid tumours less than 1 cm?
No further resection needed if complete resection by appendicectomy has been undertaken.
What types of gastric carcinoids exist?
- Type 1: Associated with hypergastrinaemia and chronic atrophic gastritis
- Type 2: Occurs with Zollinger-Ellison syndrome and MEN type 1
- Type 3: Sporadic, often metastatic at diagnosis
What treatment is indicated for small intestinal carcinoids?
Resection of the primary along with mesenteric lymphadenectomy, even in presence of liver metastases.
What is the prognosis after complete surgical resection of NET?
5-year survival rate is 83%.
What is the role of somatostatin analogues in symptom control for NETs?
They inhibit the release of peptide hormones and may induce apoptosis in tumour cells.
What are common side effects of somatostatin analogues?
- Fat malabsorption
- Gallstones
- Diarrhoea
- Dizziness
What is the response rate of chemotherapy in poorly differentiated NETs?
Response rates of 70% or more have been seen with cisplatin and etoposide based combinations.
What is targeted radionuclide therapy?
A palliative option for symptomatic patients with inoperable or metastatic tumours, using radionuclide therapy based on imaging agent uptake.
What is the role of embolisation in NET treatment?
Indicated for non-resectable multiple and hormone-secreting tumours to reduce size and hormone output.
What is carcinoid crisis and how can it be prevented?
A severe reaction due to hormone release, preventable by prophylactic administration of octreotide before surgery.
What is the most sensitive kind of CT PET for NET
Gallium dototate
