An Approach to Thyroid Nodules

An Approach to Thyroid
Nodules
April 2014
S. Ali Imran MBBS, FRCPC, FRCP(Edin)
Professor of Medicine, Dalhousie University
Division of Endocrinology & Metabolism
I have no conflict of interest to declare
Objectives
● To
learn a diagnostic approach to
thyroid nodules
● To review basic radiological and
pathological characteristics of thyroid
nodules
● Take home points are identified
through the symbol:
Thyroid nodules are
common
The crucifixion of
Saint Andrew by
Caravaggio 1607
Prevalence of Thyroid
Nodules vs. Age
Prevalence of Thyroid
Nodules vs. Age
If you are doing neck imaging for any reason
you have 1 in 2 chance of picking a nodule
Thyroid nodules are common!
Less than 5% of these nodules are
malignant (Lin JD, Thyroid, 2005)
A 41 yr old man with an
incidentaloma
Firm 4.5 CM thyroid nodule
Noticed by the FD
●  No radiation exposure
or family history of
cancer
●  No difficulty in
swallowing and no voice
change
●  TSH = 3.75
●  fT4 = 13.8
●  Anti-TPO = 112 (N = <40)
● 
Patients’ concerns upon
diagnosis are:
●  Is
it cancer?
●  Will it grow and cause problems?
●  What options do I have to remove/shrink it.
●  Will my kids inherit this?
●  I am tired all the time, is it due to this lump?
Patients’ concerns upon
diagnosis are:
●  Is
it cancer?
●  Will it grow and cause problems?
●  What options do I have to remove/shrink it.
●  Will my kids inherit this?
●  I am tired all the time, is it due to this lump?
Clues from History
Exposure to Radiation
Family History & Other Risks
Ø 
Family / Genetic predisposition
Ø  Medullary ca – 20% familial (MEN II)
Ø  Some non-medullary ca may also have
genetic predisposition. Associated with renal,
colon and breast cancer.
Ø 
Other risk factors
Ø  Iodine-rich diet – papillary ca
Ø Older age – anaplastic ca
Ø Previous diff’d thyroid ca – anaplastic ca
Ø Hashimoto’s thyroiditis – lymphoma
Ø Male Sex
Clues from the Physical Exam
Features of Concern
are:
● Irregular
or firm nodule
● Fixation to underlying nodules
● Vocal cord palsy (hoarseness of voice)
● Neck lymphadenopathy
Clues from the blood work
Blood work seldom
helps
● Low
TSH level indicating thyrotoxicosis
reduces the risk of malignancy
● Positive thyroid antibodies are weakly
associated with thyroid malignancy
US can be helpful in identifying
malignancy
Normal Thyroid
Transverse View
Sonographic Features of
Benign Thyroid Nodules
●  Regular,
well-defined
margins
●  Isoechoic with normal
thyroid
●  Hypoechoic rim (halo)
●  ? Smaller than 1 cm
A benign looking nodule
Peripheral Calcification in a
Benign Nodule
Surgical Specimen
Benign Thyroid Adenoma
Sonographic Features
of Thyroid Cancers
● Hypoechoic
vs. normal
thyroid
● poorly defined, irregular
margins
● punctate calcifications
Papillary Carcinoma:
Microcalcifications
Papillary Carcinoma:
Sonographic Features
Thyroid Cancer
Clues from the nodule size
Risk of malignancy is similar in
small or large nodules
However, given the excellent prognosis
of carcinoma in nodules <1CM,
aggressive investigation of subcentimeter nodules is not warranted
unless in high risk individuals.
Leenhardt L et al, J Clin Endo Metab 1999
ATA guidelines 2009
Clues from the Uptake Scan
Diffuse uptake
Uptake at 6 h = 30% (10 -20%)
Thyroid Uptake & Scan
Diffusely increased uptake
with a cold spot
Nodular Thyroid
Multiple Cold Nodules
Thyroid uptake on PET
Work up for lung ca
Work up for lung ca
The risk of thyroid cancer with positive
PET scan is roughly 30%
Are C et al, Ann Surg Oncol 2007
The Value of Uptake
Scan
● A
‘hot’ nodule is a benign nodule
● Most ‘warm’ and ‘cold’ nodules are
benign but malignancy is possible.
Step 1: Exclude thyrotoxicosis
Thyroid nodule
Check TSH
TSH suppressed
TSH normal
Radio-uptake scan
US scan
If ‘hot’ - treat
If ‘cold’ - FNA
TSH is a risk factor for cancer
A 41 yr old man with an
incidentaloma
Firm 4.5 CM thyroid nodule
Noticed by the FD
●  No radiation exposure
or family history of
cancer
●  No difficulty in
swallowing and no voice
change
●  TSH = 3.75
●  fT4 = 13.8
●  Anti-TPO = 112 (N = <40)
● 
Step 2: Assess US characteristics
Thyroid USS
>1-1.5 CM OR
Risky features
Perform FNA
<1-1.5 CM OR
No risky features
Observe
Thyroid USS
Step 3: Perform an FNA
Thyroid FNA
Benign
Follow for 2-3 years
Abnormal
Repeat FNA or
Surgery
Cancer
Surgery
Thyroid FNA
25 g needle
1 ml suction
Thyroid FNA
Ultrasound-guided FNA:
QE II Thyroid FNA reporting system
Benign Hyperplastic Nodule
Colloid
Microfollicular adenoma
‘Abnormal’
Follicular adenoma
‘Abnormal’
Hurthle cell neoplasm
‘Abnormal’
Granular cytoplasm
Papillary Thyroid Ca
Nuclear grooves
Nuclear Inclusions
Medullary Thyroid Ca
How to follow benign nodules
Thyroid FNA
Benign
Follow for 2-3 years
Abnormal
Repeat FNA or
Surgery
Cancer
Surgery
After Biopsy
● If
a nodule is reported as
‘benign’, it is advisable to
follow it clinically for 3 years
● Most nodules reported as
‘abnormal’ or ‘indeterminate’
are benign but should be
excised.
● Always discuss the report
with a specialist.
Why should I follow a
‘benign’ nodule?
● Thyroid
FNAB is not 100% specific and
it is possible to miss malignancy in
larger nodules. An enlarging nodule
even if ‘benign’ should be re-biopsied
or excised.
Patients’ concerns upon
diagnosis are:
●  Is
it cancer?
●  Will it grow and cause problems?
●  What options do I have to remove/shrink it.
●  Will my kids inherit this?
●  I am tired all the time, is it due to this lump?
Enlargement of benign thyroid
nodules doesn’t indicate
malignancy!
Almost 90% of nodules enlarge by up
to 15% over 5 years.
Indications of repeat FNA
of a benign nodule are:
● 
● 
● 
Enlargement of nodule by 2 mm in size
in two dimensions or >20% increase in
size.
Change in texture
New symptoms
CONTINUE TO FOLLOW FOR 3 YEARS
● If
there is no growth within 3 years after
a negative biopsy, there is no need to
continue yearly US as it will cause a lot
of anxiety and unnecessary
procedures.
Approaching a multinodular
thyroid
Approaching a multinodular
thyroid
●  Perform
FNA of larger
nodules or those with
suspicious US findings
●  Follow the rest with US scan
●  The risk of cancer is similar
to that of a single nodule
Patients’ concerns upon
diagnosis are:
●  Is
it cancer?
●  Will it grow and cause problems?
●  What options do I have to remove/shrink it?
●  Will my kids inherit this?
●  I am tired all the time, is it due to this lump?
Management options
for benign nodules
Management options
for benign nodules
● Observe
● Excision
● Thyroxine
● Radioiodine
TH suppression is not effective
in shrinking nodules
Patients’ concerns upon
diagnosis are:
●  Is
it cancer?
●  Will it grow and cause problems?
●  What options do I have to remove/shrink it?
●  Will my kids inherit this?
●  I am tired all the time, is it due to this lump?
Some thyroid cancers
are inherited
● The
usual form of thyroid cancer has a
positive family history in 5% patients.
● Medullary
thyroid cancer is inherited as
autosomal dominant
Patients’ concerns upon
diagnosis are:
●  Is
it cancer?
●  Will it grow and cause problems?
●  What options do I have to remove/shrink it?
●  Will my kids inherit this?
●  I am tired all the time, is it due to this lump?
Fatigue may be common in
autoimmune thyroid disease
Fatigue may be common in
autoimmune thyroid disease
Patients with FM are more likely to have
positive thyroid autoantibodies
Thyroid antibodies are positive
in anxiety and depression
Thyroid nodule and
fatigue
● If
your patient has positive antibody,
you should consider either FM or
depression.
● There is no evidence that treating
euthyroid individuals with thyroxine
improves fatigue
A 41 yr old man with an
incidentaloma
FNA of thyroid
Medullary thyroid ca
The End

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