Thyroid Neoplasms Flashcards
benign causes of nodules
cyst
colloid nodule
benign follicular adenoma
hyperplastic nodules
malignant causes of nodules
papillary follicular medullary lymphoma poor differentiated (anaplastic)
how to check whether a nodule is on the thyroid?
check it moves on swallowing as the thyroid is invested in the pre-tracheal fascia
what is an uncommon feature in a nodule?
pain but can be caused by an intra-thyroidal bleed into a cyst
diagnosis of neoplasm
- history: neck irradiation and FH of thyroid carcinoma
- examination: neck nodes and hoarseness
- investigation: TSH and USS-FNA for cytology or core biopsy for morphology (lymphoma)
what investigations are not used in neoplasms
isotope thyroid scan
CT/MRI
USS-FNA classification
thy1= inadequate sample thy2/U2= bengin thy3/U3= atypical thy4/U4= probably malignant thy5/U5= malignant
staging that can be used?
TNM
low risk thyroid tumours
under 50
tumour <4cm
follow-up for low risk nodules
TSH and thyroglobulin measured every 6 months for first 5 years, then annually for next 5
predictors of malignancy
- new thyroid nodule age <20 or >50
- lesion >4cm in diameter and size increasing
- male
- history of head and neck radiation
- vocal cord palsy
define adenoma
this is a benign discrete solitary mass that is often an incidental finding, but if large can cause local symptoms
what is an adenoma comprised of?
neoplastic thyroid follicles (follicular adenoma)
what is an adenoma difficult to distinguish from?
nodule in goitre
follicular carcinoma
what do some adenomas do?
secrete thyroid hormones causing thyrotoxicosis, due to mutation in TSHR signalling pathway that activates G proteins and cAMP
what age groups is thyroid carcinoma more common in?
females 15-40
males more common with age
uncommon in children
causes of carcinomas
environment
genetics
which carcinoma is associated with radiation
papillary
which carcinoma is associated with iodine deficiency
follicular
what are differentiated thyroid cancers driven by?
TSH
which is the most common carcinoma?
papillary
presentation of papillary carcinoma?
usually a solitary nodule
lymph node metastasis common
haematogenous spread rare, but usually to lung
associated with Hashimoto’s thyroiditis
survival rates from papillary carcinoma
good
buzzword for pathology of papillary carcinoma
orphan Annie eye nuclei psammoma bodies
who is follicular carcinoma most common in?
females 40-50s (older than papillary)
presentation of follicular carcinoma
slow growing
painless
non-functional nodule
haematogenous spread to bone, lungs and liver
lymph node spread rare
invasive growth pattern of vasculature/capsle
management of follicular carcinoma
thyroid lobectomy, but if significant invasion then total thyroidectomy
where are incident rates higher for follicular carcinoma?
regions of iodine deficiency
what is medullary thyroid carcinoma derived from?
C cells so can secrete calcitonin
what can MTC be associated with?
MEN2a/b
amyloid deposition of abnormally folded calcitonin
presentation of MTC
neck mass
paraneoplastic syndrome e.g. diarrhoea (VIP production) and Cushing’s (ACTH production
management of MTC
total thyroidectomy
describe anaplastic carcinoma
undifferentiated, aggressive tumours
rapid growth and involvement of neck structures
who does anaplastic carcinomas present in?
older patients usually
five types of thyroid carcinoma
papillary carcinoma follicular carcinoma medullary thyroid carcinoma anaplastic carcinoma lymphoma
risk associations with lymphoma
background of AI hypothyroidism on T4
presentation of lymphoma
rapid onset mass
usually women 70-80
diagnosis of lymphoma
core biopsy
management of lymphoma
R-CHOP chemo
radio
steroids
management of DTC
surgery is first line, options include:
- thyroid lobectomy with isthmusectomy
- sub-total thyroidectomy
- total thyroidectomy
risk stratification post-op
AMES age metastasis extent of primary size of primary tumour
AMES low risk
- younger patients (men <40 and women <50) with no metastasis
-older patients with minimally invasive lesion, tumour <5cm
add no distant metastasis
management of AMES low risk
thyroid lobectomy with isthmusectomy
AMES high risk
all patients with distant metastases
extrathyroidal disease in patients with papillary cancer
significant capsular invasion with follicular carcinoma
primary tumour >5cm in old patients
when sub-total or total thyroidectomy used in DTC?
extra-thyroidal spread bilateral/multifocal DTC DTC with distant metastasis nodal involvement AMES high risk
lymph node surgery
central lymph node clearance
post-op care
check calcium and give replacement if below 2mmol/L
discharge on T3/4
when is whole body iodine scanning used
patients who have undergone sub-total or total thyroidectomy usually 3-6 months post-op
what happens to medications before the scan?
T4 stopped 4 weeks prior to the scan
T3 stopped 2 weeks prior to the scan
rhTSH is better as no need to stop T3/T4
what level should TSH be for best results in total body iodine scanning
more than 20
lead up to whole body iodine scanning
rhTSH injections Monday/Tuesday and mCi capsule on Wednesday and patients return for imaging on Friday
results of scan inform treatment decision
describe thyroid remnant ablation
- admitted to a lead-lined room with mains sewerage
- pre-treated with rhTSH
- 2 or 3 GBq capsule of I-131 administered
side effects of thyroid remnant ablation
sialadenitis
sore throat
use disposable cutlery and no contact until no longer radioactive
discharge when count rate <500cps at 1m (Geiger counter) and post-therapy scan prior to discharge
patients maintained on T4 (below 25)
recurrent disease
- detected clinically through rising Tg or by imaging
- recurrence in cervical lymph nodes is often papillary
- haematogenous spread to lungs, bone or brain more common in follicular
- patients undergo whole body scan to determine ability of disease to take up iodine (difficult if this is negative)
- PET
systemic anti-cancer therapy (SACT)
- sorafenib and lenvatinib for patients DTC refractory to radioactive iodine therapy
