This site is intended for healthcare professionals
General Practice Notebook
Medical search

investigations

FREE subscriptions for doctors and students... click here
You have 3 open access pages.

General markers of neuroendocrine tumours

  • chromogranin A (CgA)
    • a secretory granule, is located alongside specific hormones in large dense-core vesicles of neuronal and neuroendocrine cells
    • CgA is raised in 99% of metastatic carcinoid tumours
  • other general staining markers include pancreatic polypeptide, neuron-specific enolase, peptide histidine-methionine and human chorionic gonadotrophin subunits

Specific markers of carcinoid tumours

  • carcinoid tumours secrete a variety of catecholamines, including serotonin. Diagnosis can be made on the basis of a raised 24 hour urinary level of 5-HIAA - a breakdown product of serotonin; or by whole blood serotonin
    • other urinary markers include neuropeptide K, substance P and other tachykinins
    • urinary hydroxyindole acetic acid (5HIAA) and neuropeptide K show high sensitivity in midgut carcinoid - these markers have less diagnostic usefulness in foregut and hindgut carcinoid
    • if a diagnosis of carcinoid is suspected with normal baseline urinary testing, the pentagastrin test with measurements of plasma tachykinins is a useful diagnostic measure

    Other investigations:

    • radiological localisation of carcinoid tumour
      • somatostatin-receptor-scintigraphy
        • sensitivity 90% and specificity 80%
      • CT
        • may be used preoperatively for localizing tumours- however difficulty detecting tumours <1cm
    • a liver ultrasound scan or CT scan may show evidence of secondaries in the liver.

    Reference:

    1. Endocr Relat Cancer. 2004 Mar;11(1):1-18.

    Links:

    General Practice Notebook
    General Practice Notebook
    The information provided herein should not be used for diagnosis or treatment of any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions. Copyright 2016 Oxbridge Solutions LtdĀ®. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions LtdĀ® receives funding from advertising but maintains editorial independence. GPnotebook stores small data files on your computer called cookies so that we can recognise you and provide you with the best service. If you do not want to receive cookies please do not use GPnotebook.