Synopsis
Assess thyroid nodules systematically, recognise invasive emergencies, distinguish differentiated, medullary and anaplastic biology and deliver risk-adapted surgery, radioiodine, endocrine treatment, genetics and surveillance.
- Most thyroid nodules are benign; malignancy risk is determined by clinical context, structured ultrasound appearance and ultrasound-guided cytology rather than size or thyroid function alone.
- First-line imaging for a thyroid nodule is greyscale ultrasound using an established grading system, with cervical-node survey; CT is not the routine first test for a simple nodule.
- Check TSH and thyroid function, but a normal TSH does not exclude cancer. A suppressed TSH directs assessment for an autonomous nodule and changes whether cytology is useful.
Key red flags
Stridor, inability to lie flat, drooling, cyanosis, respiratory fatigue or rapidly progressive neck swelling indicates threatened airway.
Very rapid firm enlargement, pain, dysphagia, hoarseness, stridor and fixation in an older person requires an emergency invasive-tumour pathway.
Investigation priorities
Characterise each nodule and cervical nodes using an established malignancy-risk grading system and select lesions for sampling.
Management branches
A palpable or incidental thyroid nodule is identified without immediate airway compromise.
- Take radiation, family, growth, voice and compressive history, examine thyroid and all neck levels and check TSH while arranging structured thyroid and nodal ultrasound.
- Offer ultrasound-guided FNA only when the established ultrasound threshold is met, sampling suspicious nodes as well; follow non-diagnostic and indeterminate results through repeat, core, surveillance or diagnostic surgery pathways.
Key medicines
Levothyroxine after thyroid cancer surgeryAfter total thyroidectomy, a common initial full-replacement estimate in a younger otherwise healthy adult is about 1.6 micrograms/kg orally once daily, then titrated to the histology- and response-specific TSH target; start lower in older people or cardiac disease.
Calcium and calcitriol for postsurgical hypoparathyroidismFor stable symptomatic or persistent hypocalcaemia, use a local endocrine regimen such as oral calcium providing 1 to 2 g elemental calcium daily in divided doses plus calcitriol 0.25 micrograms once or twice daily, titrated to symptoms and serial calcium.