How should I investigate a patient presenting with a thyroid nodule to determine the need for referral?

When a patient presents with a thyroid nodule, the initial investigation in primary care should include arranging serum thyroid function tests (TFTs) to assess thyroid status. This helps guide the referral pathway and further management. If the patient has symptoms of upper airway obstruction (e.g., stridor), arrange emergency hospital admission immediately.

Urgent specialist referral (within 2 weeks) to a thyroid surgeon or endocrinologist is indicated if there is:

• An unexplained thyroid lump.
• A thyroid mass with unexplained hoarseness or voice change.
• A thyroid mass associated with cervical or supraclavicular lymphadenopathy.
• Sudden onset of a rapidly expanding painless thyroid mass.
• A thyroid nodule with other red flags or risk factors for malignancy.
• A thyroid nodule causing compressive symptoms such as breathlessness or dysphagia.

For children with a thyroid nodule or goitre, arrange an urgent referral to a paediatric endocrinologist or general paediatrician depending on local services.

For adults with a non-suspicious thyroid nodule:

• If TFTs are abnormal, arrange a routine endocrinology referral as the risk of malignancy is low.
• If TFTs are normal, also arrange routine referral.
• If the nodule is incidentally found on imaging and is >1 cm without suspicious features, consider referral.

Monitoring in primary care without referral may be appropriate if the nodule is longstanding, stable, non-suspicious, and there are no red flags or risk factors for malignancy, or if the nodule is <1 cm, asymptomatic, and incidentally found without lymphadenopathy or other risk factors.

Do not routinely arrange neck or thyroid ultrasound in primary care as this may delay diagnosis; ultrasound and further investigations are generally arranged by specialists.