Tumour markers: carcinoid, GI hormone and endocrine neoplasia
How to order and read urine 5-HIAA, chromogranin A, fasting gastrin and the other gut hormones, calcitonin, CEA and thyroglobulin, with the false positives (food, PPIs, renal failure) that make most abnormal results wrong.
Tier 2Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Tumour markers here follow a known tumour or confirm a suspected syndrome. Almost none is a screening test.
- Most abnormal results come from food, drugs or organ failure. PPIs alone raise chromogranin A, gastrin and calcitonin.
- Urine 5-HIAA for carcinoid syndrome; chromogranin A to follow a tumour that secretes it; gastrin with gastric pH for gastrinoma; calcitonin and CEA for medullary thyroid cancer; thyroglobulin with antibodies after differentiated thyroid cancer.
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Sources
- ENETS consensus guidelines for the standards of care in neuroendocrine tumours: biochemical markersNeuroendocrinology (Oberg K, et al.; 105:201-11), 2017 (no newer ENETS biomarker paper at November 2026)
- European Neuroendocrine Tumor Society (ENETS) 2022 guidance paper for carcinoid syndrome and carcinoid heart diseaseJournal of Neuroendocrinology (Grozinsky-Glasberg S, et al.), 2022
- ENETS 2023 guidance paper for functioning pancreatic neuroendocrine tumour syndromesJournal of Neuroendocrinology (Hofland J, et al.), 2023
- ENETS 2024 guidance paper for the management of well-differentiated small intestine neuroendocrine tumoursJournal of Neuroendocrinology (Lamarca A, et al.), 2024
- Revised American Thyroid Association guidelines for the management of medullary thyroid carcinomaThyroid (Wells SA, et al.; 25:567-610), 2015 (still current at November 2026)
- 2025 American Thyroid Association management guidelines for adult patients with differentiated thyroid cancerThyroid (Ringel MD, et al.; 35:841-985), 2025
- Evaluation and management of adult hypoglycemic disorders: an Endocrine Society clinical practice guidelineJournal of Clinical Endocrinology and Metabolism (Cryer PE, et al.), 2009
- RCPA Manual (pathology test interpretation)AU/NZRoyal College of Pathologists of Australasia
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Turnstile bot check on sign-in and signed-out feedback