What are the indications for thyroidectomy in multinodular goiter (MNG) of the thyroid?

Indications for Thyroidectomy in Multinodular Goiter (MNG)

Total or near-total thyroidectomy is indicated for multinodular goiter when there are suspicious features on ultrasound, compression symptoms, cosmetic concerns, or hyperthyroidism that cannot be adequately managed with other treatments. 1

Primary Indications

• Suspicious features for malignancy:

  • Suspicious ultrasound findings in any nodule within the MNG 1
  • Follicular neoplasia on fine needle aspiration cytology (FNAC) with normal TSH and "cold" appearance on thyroid scan 1
  • Presence of cervical adenopathy 1

• Compressive symptoms:

  • Dyspnea, orthopnea, obstructive sleep apnea 1
  • Dysphagia due to esophageal compression 1
  • Dysphonia due to recurrent laryngeal nerve involvement 1
  • Tracheal compression 1

• Substernal or retropharyngeal extension:

  • CT or MRI confirmation of extension beyond normal thyroid boundaries 1
  • Deep extension affecting surrounding structures 1

• Toxic multinodular goiter (Plummer's disease):

  • Hyperthyroidism with autonomous nodular function 2, 3
  • Large goiters with large autonomously functioning nodules 4

• Cosmetic concerns:

  • Visible neck deformity causing psychological distress 2
  • Large nodules causing cosmetic problems 2

Secondary Indications

• Nodule size and growth:

  • Nodules with maximal diameter ≥2 cm that are increasing gradually 1
  • Large MNG unlikely to respond to non-surgical treatments 2

• Incidental thyroid carcinoma risk:

  • The prevalence of incidental thyroid carcinoma (2.12%) in MNG patients may justify more radical surgical approaches to avoid reoperation 5

• Failed medical management:

  • Recurrent nodules after chemical ablation 1
  • Ineffective levothyroxine suppression therapy 4

Special Considerations

• Imaging assessment before surgery:

  • Ultrasound is the preferred first-line imaging modality for suspected goiter 1
  • CT is superior to ultrasound for evaluating substernal extension and tracheal compression 1
  • MRI is an alternative to CT but has more respiratory motion artifact 1

• Surgical approach:

  • Total or near-total thyroidectomy is recommended for most cases of MNG requiring surgery 2
  • The Dunhill operation (total lobectomy and contralateral subtotal resection) or subtotal thyroidectomy may be considered in select cases, but carry higher risk of requiring completion surgery if incidental cancer is found 5

• Potential complications:

  • Transient hypocalcemia (11%) 2
  • Permanent hypocalcemia (0.6%) 2
  • Temporary recurrent laryngeal nerve palsy (6.4%) 2
  • Permanent recurrent laryngeal nerve palsy (1.9%) 2
  • Hematoma (0.6%) and seroma (1.3%) 2

• Alternative treatments to consider:

  • Radioiodine (131I) therapy may be effective for toxic MNG, particularly in poor surgical candidates 6, 3
  • Thermal ablation techniques may be considered for benign nodules causing compression or cosmetic concerns in patients who refuse surgery 1, 6

Preoperative Assessment

• Vocal cord mobility assessment:

  • Consider evaluation of vocal cord mobility via ultrasound, mirror indirect laryngoscopy, or fiberoptic laryngoscopy before surgery 1

• Laboratory evaluation:

  • Thyroid function tests (TSH) 4, 3
  • Fine needle aspiration cytology for suspicious nodules 1

By following these evidence-based indications for thyroidectomy in multinodular goiter, clinicians can optimize patient outcomes while minimizing unnecessary surgical procedures and their associated risks.