Aetiology

• Very common; affect 5% of women
• Vast majority (95%) are benign
• Malignant thyroid nodules can can affect any age group; there is a higher incidence in females after childhood and before older age

Pathophysiology

Benign thyroid nodules (95%)

• Cyst
• Colloid nodule
• Benign follicular adenoma
• Hyperplastic nodule

Features of benign nodules

• Family history autoimmune disorders
• Family history benign nodules/goitre
• Associated hormonal disturbance
• Pain/tenderness
• Soft, smooth, mobile

Malignant thyroid nodules (5%)

• Papillary thyroid carcinoma (80%)
• Medullary thyroid carcinoma (3%)
• Lymphoma - primary (5%) or secondary