Thyroid Nodules

Question 1

What are the two types of thyroid nodule?

Answer 1

Solitary thyroid nodule

Multi-nodular goitre

Question 2

Are there more benign or malignant thyroid nodules?

Answer 2

95% benign

Question 3

What are the types of benign solitary thyroid nodules?

Answer 3

Thyroid cyst
Colloid nodule
Benign follicular adenoma
Hyperplastic nodule

Question 4

What are the types of malignant solitary thyroid nodules?

Answer 4

Papillary thyroid carcinoma
Follicular thyroid carcinoma
Medullary thyroid carcinoma
Lymphoma
Anaplastic thyroid carcinoma

Question 5

How would you tell if a nodule in the neck is in the thyroid or not?

Answer 5

Ask patient to swallow - if it moves it is in the thyroid

Pain is uncommon in thyroid nodules

Question 6

What is pain usually caused by if present in a thyroid nodule?

Answer 6

Intra-thyroidal bleed into a cyst

Question 7

What are risk factors for thyroid carcinomas?

Answer 7

Neck irradiation

Family history

Question 8

What are the signs and symptoms of thyroid carcinomas?

Answer 8

Nodule in neck
Hoarseness
Enlarged cervical lymph nodes

Question 9

What investigation is done for suspected thyroid carcinoma?

Answer 9

TSH levels
Ultrasound guided fine needle aspiration
May need core biopsy for lymphoma

Question 10

What are the FNA classifications and what likelihood of carcinoma do they indicate?

Answer 10

Thy1 - inadequate sampling
Thy2 - benign
Thy3 - atypical, more investigation needed
Thy4 - probably malignant
Thy5 - malignant

Question 11

What factors indicate low risk of malignancy?

Answer 11

Aged <50
Tumour <4cm
TSH lower range of normal, baseline thyroglobulin

Question 12

What factors indicate high risk of malignancy?

Answer 12

Aged >50
Tumour >4cm
TSH <1

Question 13

What is the treatment for low risk patients?

Answer 13

Thyroid lobectomy

Question 14

What is the treatment for high risk patients?

Answer 14

Total thyroidectomy

Consider radioactive iodine

Question 15

In follow up of differentiated thyroid cancer, what substances should be at what level?

Answer 15

TSH - keep at lower end ofnkormal (0.4-4)

Thyroglobulin - keep low

Question 16

What can be an indication of recurrence of thyroid caner?

Answer 16

Rising levels of thyroglobulin

Question 17

What is a risk factor for thyroid lymphoma?

Answer 17

Background of autoimmune hypothyroidism

Question 18

What is the usual presentation of a thyroid lymphoma?

Answer 18

Rapid onset of mass in the thyroid

Question 19

What is the treatment for thyroid lymphoma?

Answer 19

Steroids
Chemotherapy
Radiotherapy

Question 20

What is medullary thyroid carcinoma?

Answer 20

A tumour of the parafollicular cells

Question 21

What is the tumour cell marker for medullary thyroid carcinomas?

Answer 21

Calcitonin (the substance c cells secrete)

Question 22

What are the types of medullary thyroid carcinoma?

Answer 22

Sporadic
Familial non-MEN
MEN
MEN2a

Question 23

What is MEN2a medullary thyroid carcinoma associated with?

Answer 23

Phaeochromocytoma
Hyperparathyroidism
Mucosal neuromas

Question 24

How can multi-nodular goitres function?

Answer 24

Over or underactive

Toxic

Question 25

What symptoms can be caused by compression of structures by a multi-nodular goitre?

Answer 25

Stridor | Chocking lying flat

Question 26

What are TSH levels in multi-nodular goitres?

Answer 26

Usually normal or slightly suppressed

Question 27

What signs of a multi-nodular goitre can be seen on CT scan?

Answer 27

Retrosternal extension | Tracheal compression

Question 28

What is the treatment for multi-nodular goitre?

Answer 28

Most can be left alone Radioactive iodine if significant hyperthyroidism Surgery if structural problem

Question 29

What are indications for surgery for multi-nodular goitre?

Answer 29

Lifestyle interfering symptoms Possibility of cancer Significant tracheal compression

Question 30

What are the two most common thyroid carcinomas?

Answer 30

Papillary (76%) | Follicular (17%)

Question 31

What does 'differentiated thyroid carcinoma' (DTC) refer to?

Answer 31

Papillary and follicular carcinomas | Both well differentiated and look very similar to normal histology

Question 32

How do DTCs function?

Answer 32

Take up iodine and secrete thyroglobulin

Question 33

What is the prognosis like for DTCs?

Answer 33

Very good

Question 34

What are risk factors for DTCs?

Answer 34

Exposure to radiation | No other strong associations

Question 35

What is the usual presentation of DTCs?

Answer 35

Palpable nodules | Some are incidental findings

Question 36

How do papillary thyroid cancers spread?

Answer 36

Lymphatics | Can spread by haematogenous spread to lungs, brain, liver, bone

Question 37

What condition is papillary thyroid cancer associated with?

Answer 37

Hashimoto's thyroiditis (autoimmune hypothyroidism)

Question 38

How do follicular thyroid cancers spread?

Answer 38

Haematogenous route | Lymphatic spread is rare

Question 39

What are the surgical options for thyroid cancer?

Answer 39

Thyroid lobectomy with isthumectomy Sub-total thyroidectomy Total thyroidectomy

Question 40

What is the post-operative care for thyroid cancer?

Answer 40

Check calcium within 24 hours Start calcium replacement if it falls below 2mmol/l Discharge on T3 or T4

Question 41

When is whole body iodine scanning done?

Answer 41

In patients who have undergone sub-total or total thyroidectomy

Question 42

What is done before whole body iodine scanning and why?

Answer 42

TSH levels are raised with synthetic TSH to ensure sensitivity of the thyroid to iodine

Question 43

What is the purpose of whole body iodine scanning?

Answer 43

Will show any areas of thyroid cancer activity

Question 44

What is thyroid remnant ablation?

Answer 44

A treatment for thyroid cancer involving radiation that can ablate residual thyroid tissue to destroy microfoci that surgeons can't see

Question 45

What are the side effects of thyroid remnant ablation?

Answer 45

Siladenitis (painful salivary glands) | Sore throat