Thyroid nodules

Question 1

What is a thyroid nodule

Answer 1

• Solid or fluid filled lump in thyroid gland - may be cancerous

Question 2

How common is it

Answer 2

4-7% adults have palpable lumps

Question 3

What causes it

Answer 3

• Iodine deficiency
• Thyroid malignancy
• Thyroiditis
• Thyroid cyst
• Over growth normal tissue

Question 4

What questions do you have to ask?

Answer 4

1. Smooth or nodular
2. Is pt euthyroid (norm functioning gland), thyrotoxic or hypothyroid
   a. Smooth, non toxic goitre = iodine def, congenital, thyroiditis, physiological, Hashimoto’s thyroiditis
   b. Smooth, toxic – Grave’s disease
3. Any nodules? Many or 1? If >4cm = likely cancer

DIFFUSE
• SIMPLE = no clear cause, usually smooth + soft? Ass with thyroid growth stimulating Ab
• AUTOIMMUNE = Hashimoto’s thyroiditis + thyrotoxicosis (Graves) – ass with firm, diffuse goitre variable size
• THYROIDITIS = acute tenderness/ pain in swelling = acute viral thyroiditis (de Quervain’s disease) –< may produce transient clinical hyperthyroidism with serum ^ in T4

NODULAR
• Multinodular – most common, usually euthyroid –> may cause oesophageal/ trachea compression + laryngeal palsy (coarse voice)
• Solitary: Single thyroid lump – common but hard Dx treat as malignant although maj are cysts/ adenoma/ benign
• Fibrotic: REIDEL’S THYROIDITIS – rare ‘woody’ gland, irregular + hard
- Ass w/ systemic symptoms inflammation + inflammatory markers

MALIGNANCY
• Rapid enlargement, lymph node involvement, PAINFUL
- RISK F = prev irradiation, long-standing iodine def, + FHx
- LUNG + BONE = most common sites for metastases

Question 5

What’s the pathophysiology of thyroid lumps

Answer 5

• Look at cancer flash cards

ANTERIOR TRIANGLE
• Submandibular region = submandibular stones
• Pulsatile: carotid aneurysm, tortuous carotid artery, chemodectoma
• Non-pulsatile:
-Midline = dermoid cyst, thyroid gland, thyroglossal cyst, pharyngeal pouch
-Not-Midline – brachial cyst

POSTERIOR TRIANGLE

• Cystic hygroma
• Cervical rib
• Subclavian artery aneurysm
• Pancoast’s tumour

Question 6

What are the symptoms

Answer 6

• Oft asymptomatic - incidental finding

Question 7

What investigations would you perform

Answer 7

• Palpation of thyroid lumps
• TFTs + auto-antibodies
• Radioactive iodine scan - hot = hyper-function –> indicates adenoma
• USS - solid, cystic, complex
• FNA + cytology on fluid

Question 8

What is the treatment

Answer 8

• treat underlying cause
• Surgery - if malignancy suspected (otherwise watch + wait)
• Hyperthyroidism w. methimazole or carbimazole