Endocrine surgery

Question 1

Thyroid Ca.

Answer 1

Asymptomatic thyroid nodule
Risk fx: female, head/neck irradiation

Sx: dysphagia (pressure on oesophagus), voice hoarseness (pressure on recurrent laryngeal n), dyspnoea (pressure on teachea)
Signs: cervical lymphadenopathy

Ix: TSH (normal) 
Fine needle aspiration 
Papillary Ca: Orphan Annie eyes, psammoma bodies
Follicular: no coilloid 
Medullary +ve for calcitonin
US neck (size, nodular, cystic) 
Laryngoscopy (paralysed vocal cord)

Papillary 
Most common 
Assoc. BRAF gene
Young adults
Well differentiated
Spreads via LNs

Follicular
Assoc. PPAR gene
Middle aged
Spreads haematogenously

Medullary
Assoc. with RET gene, MEN2
Originates in parafollicular C cells

Anaplasitc
Rare, aggressive
Elderly
Erodes into recurrent laryngeal nerve, trachea

Lymphoma
B-cell Non Hodgkin’s. Arises from Hashimoto’s

Tx:
Hemithyroidectomy or total thyroidectomy + radio-iodine ablation + TSH suppression (levothyroxine)
Complications: bleeding, damage recurrent laryngeal nerve, hypoparathyroidism

Radio-iodine (4-6 weeks after surgery) - requires TSH to be high (allows uptake of radio-iodine), so need to stop exogenous thyroid hormone therapy before

TSH needs to suppressed after, as can stimulate malignant thyroid tissue to grow. So give Levothyroxine to suppress TSH levels

Metastatic:
1st line: radioactive iodine + TSH suppression +/- surgery (if resectable)
2nd line: Sorafenib (protein kinase inhibitor)

Question 2

Benign thyroid disease

Answer 2

Thyroglossal cyst

Moves upwards when pt protrudes the tongue
Moves upwards when pt swallows (attached to pretracheal fascia)

Multinodular goitre
Enlarging thyroid causes pressure:
- dysphagia
- SOB (especially retrosternal extension)
- Orthopnoea (gland presses on trachea when lying flat)
- Hoarseness
- Stridor
- Facial congestion (Perberton’s sign - venous engorgement esp when raising arms as obstructs thoracic outlet)

Ix: TSH low 
CT neck (size of goitre)

Question 3

Parathyroid

Answer 3

Ix: 
Serum PTH, Ca2+
Serum Phosphate 
Sestamibi scan (parathyroid scintigraphy) - solitary parathyroid adenoma 
US
CT

Tx:
Unilateral neck exploration 
Bilateral neck exploration 
Parathyroidectomy 
Complications: 
Hypocalcaemia 
Recurrent laryngeal nerve palsy