Symptoms of Thyroid Cancer
Most thyroid cancers present as asymptomatic thyroid nodules discovered incidentally on imaging, but when symptoms occur, they typically include a palpable neck mass, compressive symptoms (dysphagia, dyspnea, hoarseness), or cervical lymphadenopathy. 1, 2
Clinical Presentation by Cancer Type
Differentiated Thyroid Cancer (Papillary and Follicular)
- Asymptomatic thyroid nodule is the most common presentation, often discovered incidentally during imaging for unrelated conditions 3, 4
- Palpable neck mass that may be firm or irregular on examination 1
- Cervical lymphadenopathy indicating nodal metastases 5
- Most patients have normal thyroid function and are clinically euthyroid 2
- Vocal cord paralysis may occur if the recurrent laryngeal nerve is involved 6, 5
Medullary Thyroid Cancer (MTC)
- Palpable thyroid mass with or without cervical lymph nodes 6
- Diarrhea in some cases due to calcitonin secretion 6
- May present with symptoms of associated endocrine syndromes (pheochromocytoma symptoms like hypertension, palpitations) in hereditary MEN 2A or 2B cases 2
- Often diagnosed at more advanced stage with lymph node involvement already present 6
Anaplastic Thyroid Cancer (ATC)
- Rapidly enlarging, hard neck mass that is typically fixed and invasive 6
- Severe compressive symptoms including:
- Dyspnea as a presenting symptom predicts worse prognosis 6
- 50% present with distant metastases at diagnosis, most commonly to lungs, bones, liver, and brain 6
- Symptoms develop rapidly over weeks to months 6
Red Flag Symptoms Requiring Urgent Evaluation
- Rapid growth of a thyroid nodule over weeks to months suggests anaplastic transformation 6
- Fixed, hard mass that does not move with swallowing indicates extrathyroidal extension 6
- Stridor or severe dyspnea indicating airway compromise requires immediate assessment 6
- History of head/neck irradiation increases malignancy risk and warrants thorough evaluation 5
- Family history of thyroid cancer or MEN syndromes, particularly in younger patients 5, 2
Treatment Overview
Differentiated Thyroid Cancer
- Total or near-total thyroidectomy is the primary treatment for tumors ≥1 cm or those with high-risk features 1, 5
- Radioactive iodine (RAI) ablation for high-risk patients to eliminate remnant tissue and microscopic disease 1, 2
- TSH suppression therapy with levothyroxine to prevent tumor growth 5, 2
- Active surveillance may be considered for papillary microcarcinomas <1 cm in select low-risk patients, though younger patients (<40 years) have higher progression risk 5
Medullary Thyroid Cancer
- Total thyroidectomy with bilateral central lymph node dissection (level VI) is standard 1, 2
- Genetic testing for RET mutations to identify hereditary cases and screen family members 2
- Vandetanib or other tyrosine kinase inhibitors for advanced/metastatic disease 6, 1
- Do NOT use TSH suppression as C cells lack TSH receptors 2
Anaplastic Thyroid Cancer
- Palliative care should be initiated early given the uniformly fatal prognosis (median survival 5 months) 6
- Surgery only if resectable for local control, but most cases are unresectable at presentation 6
- Lenvatinib (preferred) or sorafenib for BRAF V600E-mutated ATC 6
- Airway management is critical; tracheostomy may be needed for impending obstruction 6
- Multimodal therapy with surgery, chemotherapy (doxorubicin ± cisplatin), and radiotherapy has disappointing results but may be attempted 6
Common Pitfalls to Avoid
- Do not dismiss small nodules in high-risk patients (radiation history, family history, suspicious ultrasound features) as these require FNA even if <1 cm 1, 5
- Avoid iodinated contrast CT when RAI therapy is planned, as it delays treatment by 2-3 months 6, 2
- Do not perform prophylactic thyroidectomy without genetic testing in suspected hereditary MTC cases 2
- Avoid overtreatment of papillary microcarcinomas in elderly or low-risk patients where active surveillance may be appropriate 1, 5
- Do not delay airway assessment in patients with rapidly growing thyroid masses, particularly ATC 6