Synopsis
Distinguish the major thyroid cancer phenotypes, recognise airway-threatening disease and route investigation, surgery, surveillance and genomic treatment through the correct specialist pathway.
- Papillary and follicular cancers arise from follicular cells and are grouped as differentiated thyroid cancer; papillary disease commonly spreads to cervical nodes, whereas follicular carcinoma more characteristically spreads haematogenously.
- Medullary thyroid cancer arises from parafollicular C cells, may secrete calcitonin and CEA, and can be sporadic or associated with germline RET variants and MEN2; family implications begin at diagnosis.
- Anaplastic thyroid cancer is an aggressive, rapidly progressive malignancy in which airway, swallowing, voice and performance status must be assessed immediately rather than after a routine diagnostic sequence.
Key red flags
A hard or fixed nodule, rapid enlargement, cervical lymphadenopathy, persistent hoarseness, dysphagia, stridor, childhood neck irradiation or relevant familial syndrome increases concern. Normal thyroid function does not lower the structural risk enough to avoid imaging.
Investigation priorities
Characterise the thyroid lesion and cervical lymph-node compartments before biopsy or operation.
Management branches
A palpable or incidentally detected thyroid lesion without current airway compromise.
- Take focused history and examination, check TSH, and arrange high-quality ultrasound that includes the central and lateral cervical nodes.
- Biopsy lesions meeting the local ultrasound threshold and any suspicious node; obtain an expedited thyroid MDT opinion for malignant, suspicious or discordant results.
Key medicines
Levothyroxine after differentiated cancer treatmentIndividualised specialist dose titrated to the agreed TSH target and free T4, rather than a universal suppressive regimen.
Radioactive iodine-131Administered only by an authorised nuclear-medicine service at an activity selected from pathology, recurrence risk and local protocol.