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.
- Offer ultrasound-guided FNA when the established ultrasound threshold is met; the definitive distinction between follicular adenoma and carcinoma requires histological capsular or vascular invasion.
- Do not measure calcitonin routinely for every nodule under NICE NG230; measure it when family history, ultrasound or another feature raises medullary thyroid cancer.
- Papillary and follicular cancers are differentiated follicular-cell tumours; medullary cancer arises from C cells, and anaplastic cancer is a separate rapidly invasive emergency.
- Surgery ranges from active surveillance or hemithyroidectomy for selected low-risk disease to total thyroidectomy with therapeutic node management for higher-risk disease.
- Radioactive iodine is selective, not automatic after every differentiated cancer, and has no therapeutic role in medullary or anaplastic carcinoma.
- After differentiated cancer, levothyroxine both replaces hormone and sets a response-adapted TSH target; maximal lifelong suppression is not appropriate for every survivor.
- All medullary thyroid cancer requires inherited RET consideration. If MEN2 is possible, exclude and control pheochromocytoma before thyroid surgery.
- Thyroglobulin is useful only after follicular-cell cancer in the correct anatomical and antibody context; calcitonin and CEA are used for medullary disease.
- Rapid enlargement, vocal-cord palsy or stridor needs urgent airway, core tissue and multidisciplinary planning for anaplastic cancer or lymphoma rather than routine nodule flow.
Key red flags
Stridor, inability to lie flat, drooling, cyanosis, respiratory fatigue or rapidly progressive neck swelling indicates threatened airway.
A hard fixed nodule, cervical node, vocal-cord palsy, haemoptysis, dysphagia or skin fixation suggests locally invasive malignancy.
Rapid enlargement over days or weeks, especially in an older person, raises anaplastic carcinoma, thyroid lymphoma, haemorrhage or infection.
A thyroid nodule with family history of medullary thyroid cancer, MEN2, pheochromocytoma or hyperparathyroidism requires calcitonin and genetics-directed assessment.
Perioral tingling, carpopedal spasm, stridor, seizure or QT prolongation after thyroidectomy suggests severe hypocalcaemia requiring urgent calcium treatment.
Very rapid firm enlargement, pain, dysphagia, hoarseness, stridor and fixation in an older person requires an emergency invasive-tumour pathway.
Perioral or acral tingling, cramps, carpopedal spasm, laryngospasm or seizure after surgery suggests clinically important low ionised calcium.
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.
- Discuss cytology, imaging, age, comorbidity and preference at the thyroid MDT and avoid over-treating a low-risk incidental lesion or under-treating invasive features.