Thyroid Cancer

Question 1

Define Thyroid Cancer

Answer 1

Malignancies of the thyroid, accounted for (>98%) by papillary, follicular, anaplastic and medullary tumours

Question 2

Aetiology of Thyroid Cancer

Answer 2

Underlying genetic alterations

Papillary: most common (80%), well differentiated with tendency towards lymph node involvement

Follicular (10%_: spreads through direct haematogenous invasion, can be ggressive

Anaplastic: undifferentiated neoplasm + vascular invasion, involves the recurrent laryngeal nerve and trachea, muscle, oesophagus

Medullary: Oiriginates in the thyroid parafollicular C cells (4%). Seen in MEN syndromes + secretes calcitonin

Lymphoma: associated with Hashimoto’s thyroiditis

Question 3

Risk factors for Thyroid Cancer

Answer 3

Head and neck irradiation
Female
FMHx

Question 4

Epidemiology of Thyroid Cancer

Answer 4

Most common endocrinological malignancy
More common in women
Median age of diagnosis is 51

Question 5

Symptoms of Thyroid Cancer

Answer 5

Midline neck lump 
Hoarseness of voice
Dyspnoea
Dysphagia 
Rapid neck enlargement 
Compression -> hoarseness, dyspnoea, dysphagia

FMHx of thyroid cancer

Question 6

Signs of Thyroid Cancer on examination

Answer 6

Palpable thyroid nodule that moves with swallowing
Tracheal deviation
Cervical lymphadenopathy

Question 7

Investigations for Thyroid Cancer

Answer 7

USS neck: nodule number and characteristics (hypervascularity, hypoechogenecity, irregular margins, micro-calcifications, taller than wide)
Fine needle biopsy: shows type of tumour

TFTs: TSH is normal (may be low if hot nodule), T4 and T3 normal
Serum calcitonin: high in medullary cancer

CT neck: May show lymphadenopathy

Laryngoscopy: may show ipsilateral paralysed vocal cord
I-123 thyroid scan and uptake: hot nodule rule out/in (patients who present with hyperthyroidism)
Core biopsy: confirm lymphoma if suggested by fine needle

Genetic testing: for MEN (RET)