Thyroid Cancer Surgery

Surgical definitions
Lobectomy Complete removal of one thyroid lobe including the isthmus.
Near-total lobectomy Total lobectomy leaving behind only the smallest amount of thyroid tissue (significantly less than 1 g) to protect the recurrent laryngeal nerves.
Near-total thyroidectomy Complete removal of one thyroid lobe (lobectomy) with a near-total lobectomy on the contralateral side or a bilateral near-total procedure. This should be clearly defined in the operation note.
Total thyroidectomy Removal of both thyroid lobes, isthmus and pyramidal lobe.
Subtotal lobectomy Terms are imprecise and should be avoided. The classically described subtotal procedures are inappropriate for thyroid cancer. If a total thyroidectomy is not carried out, the surgeon should document the exact extent of surgery to each lobe.
Total thyroidectomy

Surgery for papillary carcinoma
  1. Node negative cancer <=1 cm diameter (pT1) - lobectomy followed by levothyroxine therapy.
  2. Most other patients especially tumours >1 cm, multifocal disease, extrathyroidal spread, familial disease and clinically involved nodes - total thyroidectomy. Total thyroidectomy also if history of neck irradiation in childhood.
  3. Completion thyroidectomy should be offered within 8 weeks of histological diagnosis of cancer.
  4. Lobectomy alone may be appropriate for tumours >1 cm if low risk of recurrence.
  5. High risk patients (i.e. male sex, age >45, tumours >4 cm, extracapsular or extrathyroidal disease) without involved nodes, total thyroidectomy and level VI node dissection should be performed.
  6. Disease in level VI nodes discovered at surgery requires level VI node dissection. When suspicious/clinically involved nodes are apparent pre-operatively or encountered at surgery in the lateral neck, and confirmed by needle biopsy or frozen section, then a selective neck dissection (levels IIa–Vb) is recommended.

Surgery for follicular carcinoma
  1. Thy3 cytology usually mandates lobectomy, although in some cases discussion at the MDT may be indicated. FNAC cannot distinguish follicular adenoma or benign nodules from carcinoma.
  2. Frozen section examination is unhelpful when the FNAC diagnosis is a follicular lesion (Thy3).
  3. No further treatment if definitive histology reveals a follicular adenoma or a hyperplastic nodule.
  4. Follicular carcinoma <1cm with minimal capsular invasion should have lobectomy.
  5. Follicular cancer with vascular invasion should be treated with total thyroidectomy.
  6. Follicular carcinoma >4 cm should have near-total or total thyroidectomy.
  7. Low-risk patients (females, patients <45 years) with tumours <2 cm may have lobectomy alone and thyroxine therapy following MDT discussion and informed consent.
  8. Otherwise low-risk patients with tumours 2-4cm showing minimal capsular invasion - clear recommendations cannot be made.
  9. Palpable/suspicious cervical lymph nodes are dealt with in a similar manner to papillary carcinoma.
  10. Completion (contralateral) thyroid lobectomy should be offered within 8 weeks of histological diagnosis of cancer.

Surgery for oncocytic follicular (Hurthle cell) carcinoma

Oncocytic follicular (Hurthle cell) carcinomas may behave more aggressively than other histological types of DTC. Hurthle cell tumours are less likely to concentrate 131I and total thyroidectomy should be considered.

Surgery for papillary or follicular microcarcinoma

Patients with DTCs <1 cm diameter have an extremely low risk of death from thyroid cancer (0.1%) and can therefore be treated adequately by thyroid lobectomy provided that:

  • the tumour does not extend beyond the thyroid capsule;
  • there is no evidence of metastases;
  • there is no evidence of vascular invasion;
  • there is no evidence of multifocality;
  • there is no evidence of contralateral disease.

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