Synopsis
Classify neuroendocrine tumours by site, differentiation, grade, stage and hormone function, control dangerous secretory syndromes and select surgery, somatostatin analogues, radionuclide, targeted or cytotoxic therapy coherently.
- Non-functioning mass is a pivotal clue in Neuroendocrine tumours: Incidental imaging, pain, jaundice, obstruction or metastasis is more common than a classic hormone syndrome across many NET sites.
- Immediate priority in unstable Neuroendocrine tumours: Stabilise the physiological syndrome, obtain specialist endocrine-oncology input, use intravenous octreotide promptly for suspected carcinoid crisis and treat airway, shock, glucose, bleeding or obstruction through the relevant emergency pathway.
- Core biopsy with expert pathology is used early to establish differentiation, primary-site markers, mitotic count and Ki-67 proliferation index. Report well versus poorly differentiated morphology and grade on adequate tissue; small crushed samples can underestimate heterogeneity.
- Multiphase CT or MRI refines the next decision because arterial-phase imaging improves detection of hypervascular pancreatic and hepatic lesions; MRI is particularly sensitive for liver metastases.
- Build an integrated NET diagnosis: Obtain expert pathology with differentiation, mitoses, Ki-67 and site markers, repeating biopsy if small tissue conflicts with clinical behaviour.
- Plan site-specific curative treatment: Control hormone excess before anaesthesia and create a carcinoid-crisis plan for a functioning midgut or high-burden tumour.
- A major avoidable harm is carcinoid heart disease; Fibrotic tricuspid regurgitation and pulmonary stenosis lead to right-heart failure and may require valve intervention before hepatic or oncological procedures.
- A common diagnostic trap is menopause or mast-cell flushing: Flushing without secretory diarrhoea or raised syndrome-specific markers may be vasomotor, allergic, medicine-related or autonomic.
Key red flags
Episodic flushing, diarrhoea, wheeze and right-sided valvular symptoms suggest carcinoid syndrome.
Recurrent fasting confusion, seizure or low plasma glucose suggests an insulin-secreting pancreatic NET.
Multiple or refractory peptic ulcers with diarrhoea suggests gastrinoma and acid hypersecretion.
Severe abdominal pain, obstruction, mesenteric ischaemia or a fibrotic mesenteric mass requires urgent assessment.
A secretory NET patient becomes hypotensive, bronchospastic and flushed during anaesthesia, embolisation or tumour manipulation.
Rapid progression, bulky disease, very high Ki-67 or constitutional decline suggests poorly differentiated neuroendocrine carcinoma.
Profound flushing, bronchospasm, labile blood pressure and shock during tumour stress is an endocrine-oncology emergency.
Investigation priorities
Establish differentiation, primary-site markers, mitotic count and Ki-67 proliferation index.
Management branches
A biopsy, imaging finding or hormone syndrome suggests a neuroendocrine neoplasm.
- Obtain expert pathology with differentiation, mitoses, Ki-67 and site markers, repeating biopsy if small tissue conflicts with clinical behaviour.
- Stage with multiphase anatomical imaging and SSTR PET-CT for well-differentiated disease; add FDG PET when grade or tempo suggests aggressive biology.
- Confirm only clinically plausible hormone syndromes under correct conditions and offer genetics assessment when phenotype indicates inherited disease.