thyroid cancer Flashcards
what staging does FNA give
Thy1-5
what does Thy1 indicate
inadequate
what does Thy2/U2 indicate
benign
what does Thy3(a/f) / U3 indicate
atypical
what does Thy4 / U4 indicate
probably malignant
what does Thy5 / U5 indicate
malignant
what other staging is used in thyroid cancer
TNM
T1
< or = 2 cm
T2
2 < tumour < or = 4cm
T3
tumour > 4cm
limited to thyroid or minimal extra-thyroidal disease
T4a
moderately advanced disease - beyond thyroid capsule e.g. larynx/trachea/oesophagus
T4b
very advanced disease e.g. invades prevertebral fascia
N0
no regional lymph nodes
N1
regional lymph nodes
N1a
mets to pretracheal/paratracheal/prelaryngeal/delphian lymph nodes
N1b
mets to unilateral/bilateral/contralateral cervical or retropharyngeal or superior mediastinal lymph nodes
M0
no distant mets
M1
distant mets
true/false
differentiated thyroid cancers have the worst prognosis of all cancers
false - best prognosis except non-melanoma skin cancers
are females or males more prone to DTC
females
when are females most likely to get DTC
risk increases 15-40 then plateaus
when are males most likely to get DTC
increases with age
do DTCs have an association with diet/smoking/fmhx
no
what do DTCs have a high association with
radiation
most DTCs take up ____ and secrete ___
take up iodine
secrete thyroglobulin
DTCS are ___ driven
TSH
how do majority of DTCs present
palpable nodules
what is the treatment of choice for DTC
surgery
listen the DTCs in order of most common to least
Papillary Follicular Medullary Anaplastic People Find Me Annoying
what are some investigations done for thyroid cancer
USS-FNA - assess likelihood of malignancy
excision biopsy of lymph node
if vocal cord palsy pre-operative laryngoscopy
is FNA used in follicular lesions
no - relationship to capsule not assessed
what are follicular lesions automatically graded on FNA
Thy3
what does AMES take into account
Age
Mets
Extent of primary tumour
Size of primary tumour
what is in AMES low risk group
young patients with no mets (men < 40, women < 50)
older patients with intrathyroidal papillary lesion or minimally invasive follicular lesion
primary tumour < 5 cm and no mets
what is in AMES high risk
all patients with distant mets
extrathyroidal disease with papillary cancer
significant capsular invasion with follicular carcinoma
primary tumour > 5cm in older patients
TSH < 1 mU/L
what is the treatment for AMES low risk
thyroid lobectomy and isthmusectomy
what is the treatment for AMES high risk
total thyroidectomy
how soon is calcium checked after surgery
within 24 hours
when should calcium replacement therapy be initiated
if calcium falls below 2
what should be given if calcium falls below 1.8 or if symptomatic
IV calcium
what are patients discharged on after thyroid surgery
T3 or T4
when is WBIS used and for what
patients who have undergone sub-total or total thyroidectomy to determine ability of disease to take up iodine with a view to therapy
when should T4 be stopped prior to scan
4 weeks
when should T3 be stopped prior to scan
2 weeks
what should TSH be for best results
> 20
what is given as a capsule in WBIS
2-4 mCi I-131 administered 2 days prior
what is the treatment if there if iodine uptake > 0.1% in thyroid bed in WBIS
thyroid remnant ablation (TRA)
what are some precautions with TRA
lead lined room
pretreated with rhTSH
disposable cutlery, sheets, clothing
little/no contact with nurses
what is the aim for TSH and fT4 after TRA
TSH < 0.1
fT4 < 25
what is used as a tumour marker in the follow up of TRA
thyroglobulin
what are 3 side effects of TRA
sialadenitis
sore throat
small but significant increase in acute myeloid leukemia
what are 2 treatments for people with DTC refractory to iodine therapy
sorafenib
lenvatinib
what % of thyroid nodules are benign
95%
what are some examples of benign thyroid nodules
cyst
colloid nodule
benign follicular adenoma
hyperplastic nodule
what would a discrete solitary mass encapsulated by a surrounding collagen cuff be
follicular adenoma
what are follicular adenomas composed of
neoplastic thyroid follicles
what can follicular adenomas secrete and what can this cause
what would be seen on an isotope scan
thyroid hormones –> thyrotoxicosis
nodule is hot and rest of gland is suppressed
what are 3 genetic mutations that may be seen in follicular adenoma
ras
P1K3CA
TSHR signalling pathway - gain of function
orphan annie nuclei
papillary thyroid carcinoma
is papillary thyroid carcinoma usually solitary or multifocal
usually solitary but can be multifocal
how do papillary thyroid carcinomas usually spread
lymphatics
what is a risk factor for papillary thyroid carcinoma
ionising radiation
if a PTC was to spread by blood where would it go
lungs, bone, liver, brain
how would you describe PTC and what are the bodies of calcification seen called
cystic
psammoma bodies
most common histological DTC
PTC
what should you suspect if a lymph node contains thyroid tissue or psammoma body
PTC
what 4 genes are involved in the genetics of PTC
rearrangement of RET or NTKR1
activating point mutation in BRAF
mutation of RAS
how does PTC usually present
lesion in thyroid gland or cervical lymph node mets (mass)
what would be some signs of locally advanced disease
hoarse voice
dysphagia
cough
dyspnoea
what is the treatment for a microcarcinoma (<1cm)
thyroid lobectomy and isthmusectomy
what is the treatment if there is macroscopic lymph node disease
central compartment clearance and lateral lymph node sampling
what is the 10 year mortality rate for PTC
< 5%
second most common histological DTC is
FTC
how does FTC usually spread
haem –> bones, lung, liver
is a FTC usually multifocal or single nodule
single nodule
are females or males more likely to get FTC
females
what is the age group of getting FTC
40-50 (older than PTC)
FTC are seen more in areas of iodine excess/iodine deficiency
deficiency
what are some genetic mutations seen in FTC
P13k / AKT pathway mutation
ras (N-ras) mutation
Pax8 and PPARY1 translocation
what are the 2 types of FTC
minimally invasive and widely invasive
which is more common of the 2 FTCs
minimally invasive
what is the survival rate at 10 years in MIFTC
90%
MIFTC are
slowly enlarging/dont enlarge
painless/painful
functional/non-functional
slowly enlarging
painless
non-functional
what is the architecture of MIFTC
follicular architecture well differentiated with a part surrounding capsule
what may a MIFTC be difficult to distinguish from
follicular adenoma
how do most FTC present
U3Thy3f lesion and dx on lobectomy
what is the treatment for MIFTC
thyroid lobectomy + isthmusectomy (capsular invasion only)
what is the treatment for FTC is there is vascular invasion
total thyroidectomy
how does a widely invasive FTC differ in architecture
more solid architecture
less follicular
more mitotic activity
what is a tumour marker for MTC
calcitonin
MTC is a tumour of the —— cells which secrete —–
tumour of the parafollicular cells that secrete calcitonin
how would you describe the cells of MTC
spindle or polygonal cells arranged in nests, trabeculae or follicles
MTC is associated with deposition of what
amyloid
how can a MTC present
neck mass with local effects or paraneoplastic syndrome
what 2 paraneoplastic sydromes can MTC cause
VIP production –> diarrhoea
ACTH production –> cushings
how is MTC diagnosed
FNA - presence of amyloid or calcitonin +ve stains
what are the 4 types of MTC
sporadic
familial non-MEN
familial MEN 2a
familial MEN 2b
what types of MTC are more commonly seen in younger patients
familial MEN 2a/b
what age group do you see sporadic/familial non-MEN MTC
40s-50s
what is the treatment of a MTC
total thyroidectomy
what is seen in the histology of MTC
aggressive behaviour - necrosis, many mitoses, small cell morphology
what is the 5 year survivial rate of MTC
70-80%
how would you describe anaplastic thyroid carcinoma
undifferentiated and aggressive
when is anaplastic thyroid carcinoma seen
older patients
may be people with a history of DTC
how do ATCs present
rapid growth with involvement of neck structures and death
what genetics are involved in ATC
p53
B-catenin mutation
thyroid lymphoma is seen in a background of …
hypothyroidism
who is most likely to get thyroid lymphoma
females 70-80
how is thyroid lymphoma diagnosed
core biopsy
how is thyroid lymphoma treated
chemo (R-CHOP)
DXT (adjuvant radiotherapy)
steroids
how does a thyroid lymphoma present
rapid onset mass in thyroid