Thyroid tumours Flashcards
Name a benign thyroid tumour?
follicular adenoma
What are follicular adenomas comprised of?
neoplastic thyroid follicules
What can follicular adenomas lead to? Why?
thyrotoxicosis
they can secrete T3/T4
What are the genetic mutations that predispose to follicular adenomas?
ras
P1K3CA
TSHR pathway mutations
What are the symptoms of folliclar adenomas?
usually an incidental finding
if large –> can cause dysphagia
What is the most common kind of malignany thyroid cancer? Rank them
Papillary
Follicular
Medullary
Anaplastic
What can predispose to thyroid carcinomas?
ionising radiation
iodine deficiency
What are the genetic mutations that predispose to papillary carcinomas?
Ras
BRAF
RET
NTR1 rearrangement
What are the genetic mutations that predispose to follicular carcinomas?
P13K/AKT
ras
Pax 9
PPARyl translocation
What are the genetic mutations that predispose to medullary carcinomas?
MEN2
What are the genetic mutations that predispose to anaplastic carcinomas?
MEN2
p53
B-catenin
Describe papillary carcinomas?
solitary nodule often calcified with plasmalemma bodies
associated with Hashimotos thyroiditis
How do papillary carcinomas normally present?
metastesise to lymph nodes (often cervical) and present there
if large: dysphagia hoarseness cough dyspnoea
What do papillary carcinomas secrete?
thyroglobulin - as they are TSH driven and take up iodine
What is the prognosis of papillary carcinomas?
95% at 10 years
Describe follicular carcinomas?
single painless nodule that slowly enlarges
How can follicular carcinomas spread?
haematological
Who is more susceptible to follicular carcinomas? Females or males? old or young?
females
older age
In what areas is the incidence of follicular carcinomas very high?
areas of iodine deficiency
What is the prognosis of follicular carcinomas?
minimal spread - 90% at 10years
widespread - 50% at 10years
Describe medullary carcinomas?
derived from C cells and associated with amyloid deposition
What are the 2 types of medullary carcinoma? How do they present?
sporadic = solitary nodule familial = bilateral/multicentric/C cell hyperplasia
What can medullary carcinomas lead to?
paraneoplastic syndromes
- diarrhoea - VIP production
- cushings - ACTH production
Describe anaplastic carcinomas?
undifferentiated, rapid growth with involvement of neck structures
What is the prognosis of medullary carcinomas?
70-80% at 5 years
What population presents with anaplastic carcinomas?
older people
How is the treatment for thyroid carcinomas assessed?
ultrasound guided fine needle aspiration
excision biopsy of lymph nodes
What is the scoring system to assess thyroid cancers?
AMES Age Metasteses Extent of primary tumour Size of primary tumour
What is the criteria for an AMES low risk?
younger patient <40/50 with no metastasis
older patient with papillary lesion or non invasive follicular lesion and no metastesise
tumour <5cm
What is the criteria for an AMES high risk?
all patients with distant metastasis
What is the treatment for AMES low risk?
thyroid lobectomy with isthmuscetomy
What is the treatment for AMES high risk?
subtotal thyroidectomy
total thyroidectomy
What is the treatment if there is nodal involvement?
lymph node surgery plus thyroidectomy etc
What should all patients recieve after thyroid surgery?
T4 or T3
and check calcium levels - IV Ca if <1.8
whole body iodine scan should be performed 3-6months post op (if undergone a thyroidectomy)
When do T3 and T4 need to be stopped before a whole body iodine scan?
T4 = 4 weeks prior T3 = 2 weeks
Describe thyroid remnant ablation?
pre treated with rhTSH. given 2/3 GBq capsules of 1-131
after completion, patients discharged on T4
aim is to surpress T4 <0.1 mU/l and fT4 below 25
Why is thyroid remnant ablation given?
if there is any leftover thyroid tissue that the surgeon was not able to remove during the total thyroidectomy
