What are the indications for thyroid surgery?

Indications for Thyroid Surgery

Thyroid surgery is indicated for confirmed or suspected malignancy, compressive symptoms from goiter, hyperthyroidism requiring definitive treatment (particularly toxic nodular goiter or when other therapies fail), and specific hereditary conditions like MEN 2 syndromes.

Malignancy-Related Indications

Differentiated Thyroid Cancer (Papillary and Follicular)

• Total or near-total thyroidectomy is recommended when malignancy is diagnosed preoperatively and the nodule is ≥1 cm 1
• Surgery is indicated for cytology results that are suspicious for malignancy or consistent with malignancy 2
• Fine needle aspiration should be performed on nodules >1 cm or smaller nodules with suspicious clinical or ultrasonographic features to determine surgical candidacy 1

Medullary Thyroid Cancer

• Total thyroidectomy with bilateral central neck dissection (level VI) is indicated for all medullary thyroid carcinomas ≥1 cm or bilateral disease 2
• For tumors <1 cm with unilateral disease, total thyroidectomy is recommended and neck dissection can be considered 2
• More extensive lymph node dissection (levels II-V) is indicated for primary tumors ≥1 cm or when central compartment lymph node metastases are present 2

Hereditary Medullary Thyroid Cancer (MEN 2 Syndromes)

• Prophylactic total thyroidectomy is indicated for patients with RET proto-oncogene mutations, with timing based on mutation risk level 2:
  • Risk level D mutations (MEN 2B, codon 918,883, or compound heterozygous): Surgery in the first year of life or at diagnosis 2
  • Risk level B mutations (codons 609,611,618,620,630,634): Surgery by age 5 years or when mutation identified 2
  • Risk level A mutations (codons 768,790,791,804,891): Surgery may be deferred if annual calcitonin and ultrasound remain normal, no family history of aggressive disease, and family agrees 2

Benign Disease Indications

Compressive Goiter

• Surgery is recommended for goiters causing compressive symptoms including dyspnea, orthopnea, or dysphagia 3
• Substernal goiters more commonly cause compression and warrant surgical intervention 3
• Multiple studies demonstrate improved breathing and swallowing outcomes after thyroidectomy for symptomatic goiter 3
• Size alone without compressive symptoms does not mandate surgery for benign nodules 4

Hyperthyroidism

• Surgery is indicated for hyperthyroidism in the following scenarios 5, 6:
  • Toxic nodular goiter (the treatment of choice is radioiodine, but surgery is indicated when radioiodine is refused or contraindicated) 5
  • Graves' disease with large goiter causing compressive symptoms 5
  • Graves' disease when radioiodine has been refused 5
  • Need for rapid achievement of euthyroidism (surgery achieves this more rapidly than other modalities) 6
  • Desire for immediate childbearing capability 6
  • Requirement for tissue diagnosis 6

Preoperative Requirements

For Hyperthyroid Patients

• Patients should ideally be rendered euthyroid before surgery using antithyroid drugs to decrease thyroid vascularity, improve surgical planes, and prevent thyroid storm 6
• However, recent evidence suggests thyroidectomy can be safely performed in the hyperthyroid state by experienced teams when cardiovascular stability is achieved 7
• Pheochromocytoma must be excluded and treated first in MEN 2 patients before thyroid surgery to avoid hypertensive crisis 2

For Chronic Kidney Disease Patients with Hyperparathyroidism

• Parathyroidectomy (not thyroidectomy) is indicated for severe hyperparathyroidism with hypercalcemia precluding medical therapy, or calciphylaxis with PTH >500 pg/mL 2
• Preoperative imaging with 99-Tc-Sestamibi scan, ultrasound, CT, or MRI should be performed prior to re-exploration parathyroid surgery 2

Contraindications to Surgery

• Benign, non-functioning, non-compressive thyroid nodules (TI-RADS 1) do not require surgery regardless of size 4
• Very low-risk microcarcinomas (<1 cm) may be managed with active surveillance rather than aggressive surgery in appropriately selected patients 1
• Surgery should be avoided when adequate preoperative preparation cannot be achieved in high-risk hyperthyroid patients without cardiovascular stabilization 7

Critical Pitfalls to Avoid

• Do not operate on benign nodules based on size alone without compressive symptoms, malignancy concern, or thyrotoxicosis 4
• Inadequate lymph node assessment before surgery can miss clinically significant nodal disease in thyroid cancer 1
• Failure to exclude pheochromocytoma in suspected MEN 2 patients before thyroid surgery risks intraoperative hypertensive crisis 2
• Overtreatment of very low-risk microcarcinomas with aggressive surgery should be avoided 1
• Performing surgery without experienced thyroid surgeons increases complication rates significantly (surgeons performing <10 thyroidectomies annually have 4 times more complications than those performing >100 annually) 2