Thyroid cancer Flashcards
What is the effect of thyroid adenomas?
usually non functional
can secrete T3/T4 (leads to thyrotoxicosis)
What is the macroscopic appearance of a thyroid adenoma?
discreet solitary mass
encapsulated by collagen cuff
neoplastic thyroid follicles (follicular adenoma)
What is the mutation causing follicular adenomas?
Mutation in TSHR signalling pathway
What can follicular adenoma be mistaken for?
follicular carcinoma
What is the most common differentiated thyroid cancer?
papillary carcinoma
How do papillary carcinomas present?
Solitary nodule
maybe multifocal
usually cystic
may often be calcified
What mutation causes papillary carcinoma?
MAP kinase pathway activation
What is the prognosis with papillary carcinoma?
95% 10 year survival
good because it’s differentiated
What conditions are associated with papillary carcinoma?
Hashimoto’s thyroiditis
What is the mode of metasteses in papillary carcinoma
lymphatic
haematogenous
Where does papillary carcinoma metastasise to?
bones, lungs, liver, brain
What is the second most common differentiated thyroid cancer?
follicular carcinoma
What is the presentation of a follicular carcinoma?
single nodule
painless
slow growing
non functional
What is the mode of mets in follicular carcinoma?
Haematogenous
need vascular or capsular invasion
Where does follicular carcinoma metasts to?
bone, liver, lungs
nb, blood brain barrier?
What is the prognosis for follicular carcinoma?
depends on level of invasion
minimal invasion the 90% survival at 10 years
What is the etiology in Medullary thyroid carcinoma?
sporadic (40s+50s)
multiple endocrine neoplasia (MEN) (young)
Familial (40s+50s)
What is the mutation in MTC?
c cell mutation
secretes calcitionin
What is the presentation of MTC?
sporadic: solitary nodule
familial: bilateral/multicentric (c cells)
What is the histolgical appearance of MTC?
spindle cell
nest arrangement
trabeculae/follicles
What are the local symptoms of MTC?
dysphagia
hoarseness
airway obstruction
What are the paraneoplastic signs of MTC?
diarrhoea
Cushings signs
What is MTC associated with?
amyloid deposition
How common are MTCs? What grade are they?
Rare
High grade
What is the etiology of anaplastic tumours?
older patients
PMHx differentiated tumour
Why are anaplastic tumours aggressive?
undifferetiated
Why is survival poor with anaplastic tumours?
Rapid growth
Invades neck structures
What factors increase the likelihood of a thyroid tumour being malignant?
Male New nodule 50 years Vocal cord palsy Nodule increasing in size lesion >4cm Hx neck radiation
What investigations do you do in a suspected thyroid tumour?
US guided FNA
laryngoscopy if vocal nerve palsy
excision and biopsy lymph node
What test(s) is NOT done in suspected thyroid tumour?
NO isotope scan
NO CT/MRI?
How do you assess cytology and what sample is needed?
Thy1-Thy5
FNA
What is the grading of Thy1-Thy5?
Thy1-insufficient sample Thy2-benign Thy3-atypical, suspected benign Thy4-atyplical, suspected malignancy Thy5-malignant
What grade are follicular lesions and why?
All Thy3
difficult to assess
no capsule
What are the surgical options for thyroid cancer?
lobectomy and isthmusectomy
subtotal thyroidectomy
total thyroidectomy
When is lobectomy and isthmusectomy appropriate?
papillary microcarcinoma
<1cm
minimally invasive follicular carcinoma
low risk AMES
When is (sub)total thyroidectomy appropriate?
DTC and nodes DTC and distant mets Bilateral/multifocal DTC DTC with extrathyroidal spread High risk AMES
When should lymph nodes be removed?
Showing signs of macroscopic disease
use judgement
