Thyroid Nodules: a Clinical Update for Primary Care

Thyroid nodules are very common in the adult population. In the Framingham study, clinically apparent thyroid nodules were present in 6.4% of females and 1.5% of males.1 There may be even more thyroid nodules that are undetected, and postmortem studies demonstrate thyroid nodules in half of all patients.2 Many nodules can be managed in primary care, but some patients will require referral to secondary care. The aim of this article is to arm a GP with the information required to confidently assess which patients require referral, and in what timeframe. The gap between the 1.5–6.4% of palpable nodules found in the Framingham study and the 50% found at post-mortem implies that there is an enormous volume of nodules that are not clinically apparent. With the development of increasingly sophisticated imaging modalities there has been an epidemic of thyroid ‘incidentalomas’. These non-palpable nodules are seen in at least 20% of ultrasound scans, 25% of contrast-enhanced chest CTs, 15% of MRI neck scans, and 30% of PET-CT scans.3 Most patients with incidentally discovered thyroid nodules can be managed by the same principles of history and examination as those with palpable lumps. There are two exceptions to this rule, the first being incidental thyroid lumps on CT, MRI, or ultrasound scan (USS) that are <1 cm and have no associated lymphadenopathy. There is no need for …