Management of Thyroid Nodules

Question 1

How common are solitary thyroid nodules?

Answer 1

Very = affect 5% of women, 95% are benign

Question 2

What are examples of benign solitary thyroid nodules?

Answer 2

Cysts, colloid nodule, follicular adenoma, hyperplastic nodule

Question 3

What are examples of malignant solitary thyroid nodules?

Answer 3

Papillary carcinoma (80%), follicular carcinoma, medullary thyroid carcinoma, lymphoma

Question 4

What criteria are used to classify thyroid nodules?

Answer 4

U classification (U2-5)
FNA Bethseda classification (Thy1-5)

Question 5

What can be used to investigate thyroid nodules?

Answer 5

Ultrasound fine needle aspiration
Core biopsy (for lymphoma)

Question 6

What is the grading of solitary thyroid nodules?

Answer 6

Thy1 = inadequate
Thy2 = benign (U2)
Thy3 = atypical (U3)
Thy4 = probably malignant (U4)
Thy5 = malignant (U5)

Question 7

What is the low risk group for differentiated thyroid cancer?

Answer 7

Age <50, tumour <4cm

Get baseline Tg, TSH loser range, may need lobectomy

Question 8

What are some features of differentiated thyroid cancer?

Answer 8

Treated with total thyroidectomy, TSH <1mU/L, Tg measurement

Question 9

What are some scoring systems for differentiated thyroid cancer?

Answer 9

AMES, AGES, MACIS, TMN

Question 10

What are the T stages of the TMN staging?

Answer 10

T1 = tumour size <= 2cm
T2 = tumour size >2cm but <=4cm, limited to thyroid
T3 = tumour size >4cm, limited to thyroid or any tumour with minimal extrathyroidal extension
T4a = moderately advanced disease, tumour of any size extending beyond thyroid capsule into nearby soft tissue
T4b = very advanced disease, tumour invades prevertebral fascia or encases carotid arteries/mediastinal vessels

Question 11

What are the N stages of the TNM staging?

Answer 11

N0 = no regional lymph node metastases
N1 = regional lymph node metastases:
N1a = metastases to level VI
N1b = metastases to unilateral, bilateral or contralateral cervical, or retropharyngeal or superior mediastinal lymph nodes

Question 12

What are the M stages of the TNM staging?

Answer 12

M0 = no distant metastases 
M1 = distant metastases

Question 13

At what vertebral level is the central neck?

Answer 13

Level C6-7

Question 14

At what vertebral level is the lateral neck?

Answer 14

Level C2-5

Question 15

How is low risk differentiated thyroid cancer treated?

Answer 15

Thyroid lobectomy

Question 16

How is high risk (T3 or higher) differentiated thyroid cancer treated?

Answer 16

Total thyroidectomy, radioactive iodine

Question 17

What is thyroglobulin?

Answer 17

Protein precursor of T3/4, made by thyroid follicular epithelial cells, used as tumour cell marker for follow up

Question 18

What is the follow up for patients who have been treated with differentiated thyroid cancer?

Answer 18

TSH low (0.4-4mU/L)
Get TSH/Tg measured every 6 months for first five years then annually for next five years

Question 19

When can low risk differentiated thyroid cancer patients who have been treated stop follow up appointments?

Answer 19

After five years

Question 20

What does diagnosis of follicular carcinoma depend on?

Answer 20

Invasion of capsule or vascular invasion

Classified as minimally or widely invasive

Question 21

What are some features of follicular carcinomas?

Answer 21

Haematogenous spread

Uncommon to have disease

Question 22

What are some features of minimally invasive follicular carcinomas?

Answer 22

Most common type
Most present with U3 Thy3 lesion and diagnosed on diagnostic lobectomy
Can’t tell if capsular invasion on FNA

Question 23

How are minimally invasive follicular carcinomas treated?

Answer 23

Usually treated with thyroid lobectomy

If significant vascular invasion consider total thyroidectomy

Question 24

What are some features of thyroid lymphomas?

Answer 24

Background of autoimmune hypothyroidism (on T4)’ rapid onset of mass in thyroid, most commonly women aged 70-80

Question 25

How are thyroid lymphomas diagnosed and treated?

Answer 25

Core biopsy for histology diagnosis

Chemo (R-CHOP), DXT or steroids

Question 26

What are the types of medullary thyroid carcinomas?

Answer 26

Sporadic, familial non-MEN, familial MEN (MEN2a)

Question 27

What should always be checked in suspected medullary thyroid carcinoma?

Answer 27

24hr urinary metanephrine and genetics

Question 28

What can MEN2a mutations cause?

Answer 28

Medullary thyroid carcinoma, phaechromocytoma, hyperparathyroidism
Consider prophylactic thyroidectomy in child

Question 29

What should be assessed in multinodular goitres?

Answer 29

Assess function and structure

Question 30

What is TSH like in multinodular goitres?

Answer 30

Usually normal or slightly suppressed, occasionally need antithyroid drugs

Question 31

What do CT scans of multinodular goitres show?

Answer 31

Retrosternal extension, tracheal compression

Question 32

How are multinodular goitres treated?

Answer 32

Most can leave alone
RAI if significant hyperthyroid
Surgery if structural problem or significant retrosternal extension

Question 33

When is surgery offered to patients with retrosternal goitres?

Answer 33

Lifestyle interfering symptoms, possible cancer, significant tracheal compression if symptomatic, tracheal flow loops if other respiratory causes of orthopnoea, audible stridor