Pathology: Thyroid Flashcards
What investigations would you consider in pt presenting with signs of thyroid dysfunction but no features malignancy?
-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
What antibodies are tested for in thyroid disease?
anti-tsh receptor antibodies: raised in graves
Anti tpo (thyroid peroxidase) antibodies
Anti thyroglobulin
–> both non specific, can be raised in graves/hashimoto’s
Differential if thyroid US benign appearing:
Grave’s
Hashimoto’s
Toxic adenoma
Multinodular goitre
Malignant features on thyroid US
-Intranodular vascularity
-Irregular borders
-Lymph nodes
-Microcalcification
-Hypoechoic
Concerning features in pt presenting with thyroid nodule
-Endemic iodine deficiency (follicular)
-Previous radiation to head and neck (papillary)
-Child
-Man
-Change in voice
-Dysphagia
What investigation would you carry out in a pt presenting with suspected malignancy of thyroid?
Triple assessment
Clinical examination and bloods
US
FNA–> thy classification
What specific autoantibodies would you look for in pt with hashimoto’s?
Anti-TPO (thyroid peroxidase)
Antithyroglobulin antibody
What antibodies would you look for in pt with grave’s?
Graves specific:
Anti-TSHR antibody (thyroid receptor antibody)
Non specific:
TPO (thyroid peroxidase antibody)
Anti thyroglobulin
What are signs and symptoms in pt with grave’s disease
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)
How would you manage pt with grave’s disease or large toxic mulitnodular goitre?
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)
When would carbimazole be contraindicated? `
First trimester of pregnancy
What are features of deQuervain’s thyroiditis?
What would investigations show?
Pain and swelling, preceded by URTI
Initially hyper and then hypothyroid
Ix
-Raised WCC and ESR
-US normal
-Antibodies normal
What are the features of Riedel’s thyroiditis?
-Hard woody lump
-Compressive symptoms, rapidly growing (benign)
-T3, T4 low, TSH raised
WHat classification systems are you aware of that evaluate malignant potential of thyroid lump from FNA sample?
Thy classification
Thy 1-5
3: a and f
a-atypical
f-follicular cells
Thy 1+2: most likely benign
Thy 4: 85% malignant
How are stages of thy classification managed?
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)
What are the common types of thyroid cancers?
Papillary
Follicular
Medullary
Anaplastic
Lymphoma
What is the age of presentation of the different thyroid cancers?
Papillary: 20-30
Follicular: 40-50
50s and 60s: medullary
>70: anaplastic/lymphoma
What is the mode of spread of the different types of thyroid cancers?
Papillary and medullary: lymphatic
Follicular: haematogenous
Anaplastic: locally aggressive, haematogenous and lymphatic
What are the key characteristic features of papillary carcinomas of the thyroid?
Thamoma bodies
Orphan ani nuclei
Multifocal
What are the key characteristic features of follicular carcinomas of thyroid (including histology
Presents 35-45
Haematogenous spread
Has distorted follicular architecture
single nodule
How are papillary and follicular carcinomas treated?
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
What are the features and associations of medullary carcinoma of thyroid?
-MEN 2 30%, 70% sporadic
-Parafollicular C cells
-Neuroendocrine tumour, aggressive
-Lymphatic spread
-50s and 60s
How are medullary carcinomas of thyroid treated?
Total thyroidectomy, 2-7 lymph node dissection
No role for radio-iodine as not a thyroid cancer
What genes are associated with thyroid cancers?
RET gene
BRAF mutation (papillary)
Gardener’s syndrome
