Thyroid Nodules

Question 1

Definition of thyroid nodules

Answer 1

An abnormal growth of thyroid cells that forms a lump in the thyroid gland

Question 2

Aetiology/types of thyroid nodules:

Answer 2

There are benign (more common) and malignant causes of thyroid nodules:

• Benign:
‣ Multinodular goitre: A toxic multinodular goitre usually seen in elderly and in iodine deficient areas. The multiple nodules secrete thyroid hormones (PLUMMER’S DISEASE)
‣ Thyroid adenoma (accounts for 5% of nodules): A toxic adenoma is a solitary nodule that produces thyroid hormones, the rest of the gland is suppressed
‣ Cysts

• Malignant:
‣ Papillary carcinoma
‣ Follicular carcinoma

• Worldwide, IODINE deficiency is the biggest cause of goitre formation
• In more Western countries, Graves’ disease is more common

Question 3

History and Examination of thyroid nodules

Answer 3

• Most are ASYMPTOMATIC: unless toxic; hence producing excess thyroid hormones
• Goitre: Seen in multinodular goitre, would be irregular in texture
• Palpable thyroid nodule: adenoma
• Heat intolerance, weight loss and hyperplasia: due to increased metabolic rate as a result of hyperthyroidism
• Anxious or palpitations
• Oligomenorrhoea
• Diarrhoea
• Lid lag
• Warm, most skin (sweating)
• Tachycardia
• AF?
• Tremor
• Muscle weakness

• Hoarseness?

Question 4

Risk factors for thyroid nodules

Answer 4

• Iodine deficiency
• Age >40
• Head and neck radiation

Question 5

Investigations for thyroid nodules

Answer 5

• Serum TSH: would be suppressed, if not, rules out toxic multinodular goitre and toxic adenoma
• Serum T4: would be elevated due to toxic nodules producing it
• Thyroid ultrasound: can visualise the nodule/s

Question 6

Repayment for thyroid nodules

Answer 6

• Non-pregnant:
1) Radioactive iodine therapy:
• Good example of definitive treatment
• Would need to stop anti thyroid drugs prior to procedure, and resume few days after
• May need second dose in some people
• Would need to start thyroid hormone replacement

2)Thyroidectomy (also do if obstructive nodule, very large)

Question 7

Prevention and prognosis of thyroid nodules

Answer 7

Dietary iodine needed for thyroid hormone production and prevention of goitre formation

Generally good prognosis, most have resolution after treatment
Will however have long term hypothyroidism (needs replacement treatment)

Question 8

Complications of thyroid nodules

Answer 8

• Treatment related hypothyroidism
• Thyrotoxicosis/thyroid storm: if thyroid levels are not controlled
• Mass effect: can occur with large goitres, may lead to obstruction, chocking etc
• Recurrent laryngeal nerve damage with surgery
• AF