THYROID

Question 1

Thyroid nodules? Diagnosis?

Answer 1

They are detected thanks to routine physical exams, carotid Doppler US, screening neck US and incidental findings.

US helps identify hypoechogenicity, intranodular vascularity, microcalcifications and infiltrative margins.

Fine needle aspiration is a minimally invasive diagnostic procedure used to evaluate thyroid nodules, it is US guided and operator dependent.

Question 2

Cytology of thyroid nodules?

Answer 2

Changes in different regions, in Italy we use SIAPEC.

Tir1 —> non diagnostic, sample lacks sufficient cells to establish diagnosis. Repeat FNAC.
Tir2 —> benign, risk of malignancy 2%, follow up.
Tir3 —> follicular lesions but cannot differentiate between benign and malignant due to overlap. Low risk 10%, high risk 30% RM.
Tir4 —> suspicious for malignancy, RM 95%. Surgical intervention advised.
Tir5 —> malignant, positive for thyroid carcinoma.

Question 3

Benign and malignant thyroid nodules?

Answer 3

Benign :
- Colloid nodules —> most prevalent type with colloid accumulation.
- Cysts.
- Adenomas —> follicular adenomas.

Malignant :
1.Differentiated thyroid carcinoma originating from follicular cells.
- Papillary carcinoma 75%. Good prognosis.
- Follicular carcinoma 10%. Worse that papillary carcinoma.

2. Medullary carcinomas 5-10% of cases.
   - mostly sporadic, hereditary 25% associated to germline mutations like RET and syndromes like MEN2A and MEN2B.
   - elevated serum calcitonin.
3. Anaplastic carcinoma less than 5%.
   - Rare and aggressive.

Question 4

What is goitre?

Answer 4

Benignant form that thyroid nodule can take, consists of neck swelling and can be uninodular, multinodular or diffuse.
Can lead to tracheal deviation or compressive syndrome.

Treated by cervico mediastinal surgery.

Question 5

Thyroid surgery?

Answer 5

1. Total thyroidectomy
   - Indicated in symptomatic multinodular goiter, hyper functioning multinodular goiter, Graves’ disease when medication fails and malignant conditions.
2. Thyroid lobectomy (removal of one lobe)
   - Indicated in single hyper functioning nodule, nodule with indeterminate cytology Tir3 and differentiated thyroid carcinoma.
3. Isthectomy (removal only of isthmus)

Question 6

Neck dissection?

Answer 6

Surgical procedure to remove LN in neck.
1. Central Neck Compartment (Level VI): Nodes surrounding the thyroid gland.
2. Lateral Neck Compartment (Levels II, III, IV): Nodes along the jugular vein.

They are only removed when indicated, when there is suspicion or evidence of metastasis to LN.

Question 7

Postoperative consequences and complications?

Answer 7

Inevitable consequence —> hypothyroidism which must be treated with lifelong thyroid hormone replacement therapy with eutirox.

Main possible complications include damage to the recurrent laryngeal nerve which can cause vocal cord dysfunction. Can be permanent > 6 months or transient < 6 months. Can be unilateral or bilateral.
Other complications include hypoparathyroidism and hypocalcemia due to damage or removal of parathyroid glands.

Other potential complications include bleeding and neck hematoma, superior laryngeal nerve injury and wound infection.