Specific points

• Palpable nodule that moves on swallowing but not on protrusion
• Palpate for associated lymphadenopathy

Solitary Thyroid Nodule

• More common in females (F:M 4:1)
• Occur most commonly in 4th and 5th decade
• 10% in middle-aged are malignant; 50% malignant in young and elderly
• FNAC most important investigation
• Radioisotope scan differentiate cold from hot nodules

1. Causes
   • Prominent nodule in multinodular goitre
   • Cyst (caused by haemorrhage into a necrotic nodule): most are composite lesions with colloid degeneratin, necrosis or haemorrhage - only benign if completely abolished by aspiration; cytology can be false-negative in a third of malignant cysts
   • Adenoma: almost all are follicular adenomas; 2-4 encapsulated at presentation; indistinguishable from carcinomas on FNAC - need surgical excision
   • Carcinoma / lymphoma
   • Thyroiditis
2. Investigations / Management
   • Clinical examination
   • FNAC
   • Technetium radio-isotope scan
   • Treatment dependent on findings

Multinodular goitre

1. Features of the lump
   • Multinodular
   • Large in size
   • May be one nodule which is more prominent than the others
2. Check position of trachae
   • May be deviated by large multinodular goitre
   • Percuss for retrosternal extension

1. Features
   • Progression of simple diffuse goitre to nodular enlargement
   • Middle-aged women
   • Positive family history. Malignant change in 5% of untreated MNGs
   • Overactivity in parts of an MNG may lead to mild hyperthyroidism (Plummers syndrome)
   • No ophthalmic features are seen (characteristic of Grave's disease)
2. Descision to treat or not...
   • Most patients do not need any intervention
   • Patients usually present for cosmetic reasons, discomfort, tracheal compression, oesophageal compression, worries about malignanc, hyperthyroidism
3. Investigation: investigate if - prominent nodule, features suggestive of malignancy (cervical lymphadenopathy or recurrent laryngeal nerve palsy)
   • Thyroid function tests - ?hyperthyroid
   • USS - dimensions of goitre and nodules, look for cysts that can be aspirated
   • CXR - retrosternal goitre may compress the trachea
   • Radio-isotope scan: hot and cold nodules
   • FNAC - especially cold nodules
4. Treatment:
   • Non-surgical:
     1. remove goitrogens (less cabbage)
     2. Thyroxine - thought to reduce TSH feedback mechanisms
     3. Treat as Grave's disease if thyrotoxic
     4. Cyst aspiration with cytology to exclude malignancy
     5. Radio-iodine - elderly patients, those unfit for surgery
   • Surgical:
     1. Bilateral subtotal thyroidectomy with post-operative replacement of thyroxine
     2. Total thyroidectomy

Diffuse Thyroid Enlargement

1. Features
   • Diffuse enlargement (not nodular)
   • May be large
   • Non-tender
   • Palpate trachea for deviation
   • Check swallowing
   • Percuss over sternum for retrosternal extension of a large goitre
2. Causes
   • Simple colloid goitre
     1. Commonest form of thyroid abnormality
     2. Secondary to hyperplasia of gland to meed physiological demand for thyroxine
     3. Secondary to defective production of thyroid hormone
     4. Causes - Iodine deficiency (cmmonest cause worldwide), increased physiological demand - puberty, pregnancy, lactation; goitrogens (uncooked cabbage, lithium, anti-thyroid drugs); defects of thyroid hormone production
   • Grave's disease
     1. Commoner in females
     2. Polyclonal immunoglobulins against thyroid-stimulating hormone receptor which bind and stimulate the receptor (90% patients)
     3. Hyperthyroidism with goitre
     4. Thyroid eye disease
     5. Thyroid acropachy
     6. Pretibial myxoedema
     7. Normochromic normocytic anaemia, raised ESR, hypercalcaemia
     8. Other AI associations
     9. Treatment
        1. Medical - antithyroid drugs (carbimazole, propylthiouracil) to inhibit thyroid peroxidase; B-blockers
        2. Radioiodine - treatment of choice (contraindicated in pregnancy and lactation) - causes direct radiation damage to replication mechanism of thyroid follicular cells // risks: early hyperthyroidism, late hypothyroidism, late hypoparathyroidism
        3. Surgery - bilateral subtotal thyroidectomy leaving behind 4-10g of thyroid tissue; useful for patients who refuse radiation therapy, pregant patients
   • Thyroiditis (Hashimoto's, d Quervain's, Riedel's)

Indications for thyroid surgery

1. Obstructive symptoms (including retrosternal extension)
2. Suspicion of malignancy
3. Thyrotoxicosis
4. Increasing size despite thyroxine therapy (failure of medical treatment)
5. Cosmesis

Complications of thyroidectomy 

1. General
   • Anasthesia
2. Specific
   • Immediate: haemorrhage (leading to airway obstruction), recurrent laryngeal nerve palsy, hyperthyrodism (thyroid storm)
   • Early: infection, hypoparathyroidism
   • Late: hyperthyroidism, hypothyroidism, hypertrophic scarring

Essential Thyroid differences

Thyroid malignancy

Thyroid Eye disease

• Exophthalmos: secondary to retro-orbital inflammation and lymphocytic infiltration leading to oedema and increase in retrobulbar orbital contents
• Lid-lag: secondary to sympathetic overstimulation and restrictive myopathy of levator palpebrae superioris

NOSPECS classification of thyroid eye disease severity