Pathology: Thyroid

Question 1

What investigations would you consider in pt presenting with signs of thyroid dysfunction but no features malignancy?

Answer 1

-FBC, U+E, TFT
-US neck–> .FNA if appears malignant
-Autoantibodies
-Consider radioisotope scan if diagnosis inconclusive: ‘hot’ indicates graves disease, ‘cold’ can be indication of benign disease (cyst/adenoma/thyroiditis) or maligancy

Question 2

What antibodies are tested for in thyroid disease?

Answer 2

anti-tsh receptor antibodies: raised in graves

Anti tpo (thyroid peroxidase) antibodies
Anti thyroglobulin
–> both non specific, can be raised in graves/hashimoto’s

Question 3

Differential if thyroid US benign appearing:

Answer 3

Grave’s
Hashimoto’s
Toxic adenoma
Multinodular goitre

Question 4

Malignant features on thyroid US

Answer 4

-Intranodular vascularity
-Irregular borders
-Lymph nodes
-Microcalcification
-Hypoechoic

Question 5

Concerning features in pt presenting with thyroid nodule

Answer 5

-Endemic iodine deficiency (follicular)
-Previous radiation to head and neck (papillary)
-Child
-Man
-Change in voice
-Dysphagia

Question 6

What investigation would you carry out in a pt presenting with suspected malignancy of thyroid?

Answer 6

Triple assessment
Clinical examination and bloods
US
FNA–> thy classification

Question 7

What specific autoantibodies would you look for in pt with hashimoto’s?

Answer 7

Anti-TPO (thyroid peroxidase)
Antithyroglobulin antibody

Question 8

What antibodies would you look for in pt with grave’s?

Answer 8

Graves specific:

Anti-TSHR antibody (thyroid receptor antibody)

Non specific:

TPO (thyroid peroxidase antibody)
Anti thyroglobulin

Question 9

What are signs and symptoms in pt with grave’s disease

Answer 9

Systemic
-Weight loss
-Diarrhoea
-Heat intolerance
-Palpitations
-Tremor
-Muscle weakness

Thyroid eye disease
-Diplopia, exophthalmos, id retraction, lid lag

-Pretibial myxoedema
-Thyroid acropachy
-Pemberton’s sign (SVC obstruction)

Question 10

How would you manage pt with grave’s disease or large toxic mulitnodular goitre?

Answer 10

Propranolol (relief from adrenergic symptoms: tachycardia, palpitations, tremor)

Block and replace:
-Block thyroid hormone production with carbimazole
-Replace with levothyroxine

Definitive mx:
-Radioiodine (contraindicated if pregnant/caution in female of childbearing age)

Question 11

When would carbimazole be contraindicated? `

Answer 11

First trimester of pregnancy

Question 12

What are features of deQuervain’s thyroiditis?
What would investigations show?

Answer 12

Pain and swelling, preceded by URTI
Initially hyper and then hypothyroid

Ix
-Raised WCC and ESR
-US normal
-Antibodies normal

Question 13

What are the features of Riedel’s thyroiditis?

Answer 13

-Hard woody lump
-Compressive symptoms, rapidly growing (benign)
-T3, T4 low, TSH raised

Question 14

WHat classification systems are you aware of that evaluate malignant potential of thyroid lump from FNA sample?

Answer 14

Thy classification

Thy 1-5
3: a and f
a-atypical
f-follicular cells

Thy 1+2: most likely benign
Thy 4: 85% malignant

Question 15

How are stages of thy classification managed?

Answer 15

Thy 1+2: repeat FNA
3a:–> atypical –> core biopsy
3b: follicular cells, may be adenoma or carcinoma
–> hemithyroidectomy
–> if adenoma: nil further
–> if carcinoma: completion thyroidectomy
Thy 4: 85% chance malignant (total thyroidectomy)

Question 16

What are the common types of thyroid cancers?

Answer 16

Papillary
Follicular
Medullary
Anaplastic
Lymphoma

Question 17

What is the age of presentation of the different thyroid cancers?

Answer 17

Papillary: 20-30
Follicular: 40-50
50s and 60s: medullary
>70: anaplastic/lymphoma

Question 18

What is the mode of spread of the different types of thyroid cancers?

Answer 18

Papillary and medullary: lymphatic
Follicular: haematogenous
Anaplastic: locally aggressive, haematogenous and lymphatic

Question 19

What are the key characteristic features of papillary carcinomas of the thyroid?

Answer 19

Thamoma bodies
Orphan ani nuclei
Multifocal

Question 20

What are the key characteristic features of follicular carcinomas of thyroid (including histology

Answer 20

Presents 35-45
Haematogenous spread

Has distorted follicular architecture
single nodule

Question 21

How are papillary and follicular carcinomas treated?

Answer 21

Total thyroidectomy
High risk/lymph nodes: central compartment neck dissection (if papillary)
Follicular: haematogenous spread so total thyroidectomy only

Radioiodine after surgery: not if childbearing age, pregnant, looking after children, lactating

Question 22

What are the features and associations of medullary carcinoma of thyroid?

Answer 22

-MEN 2 30%, 70% sporadic
-Parafollicular C cells
-Neuroendocrine tumour, aggressive
-Lymphatic spread
-50s and 60s

Question 23

How are medullary carcinomas of thyroid treated?

Answer 23

Total thyroidectomy, 2-7 lymph node dissection
No role for radio-iodine as not a thyroid cancer

Question 24

What genes are associated with thyroid cancers?

Answer 24

RET gene
BRAF mutation (papillary)
Gardener’s syndrome

Question 25

What is most common type of thyroid lymphoma?

Answer 25

B cell non hodgkins

Question 26

What tumour markers are used to monitor prognosis of thyroid cancers?

Answer 26

Thyroglobulin: papillary and follicular
Calcitonin: medullary