Essential and optional investigations for thyroid disease
THE CONTEXT
The investigation scheme separates essential biochemical and cytological tests from optional tests selected for specific clinical findings.
Essential investigations
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Measure serum thyroid-stimulating hormone (TSH), with T3 and T4 measurement if TSH is abnormal, and assess thyroid autoantibodies.
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Perform fine-needle aspiration cytology (FNAC) for palpable discrete thyroid swellings.
Optional biochemical investigations
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Optional tests include corrected serum calcium and serum calcitonin.
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Carcinoembryonic antigen may be used as an alternative screening test for medullary cancer.
Imaging selected by presentation
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Chest and thoracic inlet radiography are listed for tracheal deviation or retrosternal goitre.
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Ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) are listed for known cancer, some reoperations and some retrosternal goitres.
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An isotope scan is indicated when a discrete swelling and thyroid toxicity coexist.