Approach to a thyroid nodule
Andy Sher
PGY-2 Family Medicine
Case
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44 y.o. woman, 2 cm nodule palpable in left
lobe of thyroid gland at annual exam –
smooth, non-tender. No lymphadenopathy
No symptoms of hyper/hypo thyroid. No
compressive symptoms
Past Med Hx: HTN
Meds: HCTZ
Fam Hx: no hx of thyroid disease
Epidemiology
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Palpable thyroid nodules – 4-7% of
population
Prevalence 19-67% - based on
nodules found incidentally on
ultrasound
4:1 women:men
Epidemiology
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Geographic areas with iodine
deficiency
Thyroid carcinoma in 5-10% of
palpable nodules
Following ionizing radiation, nodules
develop at a rate of 2% annually
Presentation
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Majority are asymptomatic
<1% cause hyperthyroidism
Neck pressure or pain if spontaneous
hemorrhage
History
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Symptoms of hyper or hypothyroidism
Previous nodules, goiters, family
history of autoimmune thyroid disease,
thyroid carcinoma, or familial polyposis
Hashimoto’s thyroiditis – association
with thyroid lymphoma
History – Red Flags
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Male
< 20 years, > 65 years
Rapid growth of nodule
Symptoms of local invasion
(dysphagia, neck pain, hoarseness)
Hx of radiation to head or neck
Family hx of thyroid CA or polyposis
Physical Exam
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Less than 1 cm usually not palpable
½ of all nodules detected by
ultrasonography not detected by
physical exam
Should also examine for
lymphadenopathy
Physical Exam
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Smooth or nodular
Diffuse or localized
Soft or hard
Mobile or fixed
Painful or non-tender
Laboratory
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TSH
Serum calcitonin if family hx of
medullary thyroid carcinoma
Do not use thyroid function tests to
differentiate benign from malignant
Radiology
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Ultrasound
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to document size, location, and
character of nodule
To determine changes in size of nodules
over time or to detect recurrent lesions
U/S guided biopsy decreases the
incidence of indeterminate specimens
Radiology
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Thyroid scan
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Can not reliably distinguish benign from
malignant nodules
Cold nodules – 5-15% are malignant
Hot nodules – almost always benign
Fine Needle Aspiration
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Should be 1st test in the euthyroid patient
Sensitivity 68-98%
Specificity 72-100%
False negative rate 1-11%
False positive rate 1-8%
Sampling errors in very large and very small
nodules – minimized by u/s guided biopsy
Treatment
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Surgical treatment indications
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Malignancy
Indeterminate cytology and suspicious
H&P
Indeterminate cytology and “cold nodule”
Toxic nodules (suppression of TSH,
symptoms – a-fib) – can use radioactive
iodine or surgery
Repeated recurrence of cystic lesions
Treatment
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Benign biopsies – can be followed
without surgery and monitored q 6
months by physical exam, u/s
Surveillance – change in nodule size
and symptoms – repeat FNA if nodule
grows.
Suppression treatment
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Post-operative suppression treatment
following resection of cancer
TSH should be maintained for target of
0.5 mU per L
Greater suppression for high risk
patients, metastatic or locally invasive
not completely removed
Suppression treatment
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For benign solitary nodule
controversial
Follow at 6 month intervals
Thyroxine to suppress TSH to 0.1 to
0.5 mU per L for 6-12 months
After 12 months, maintain TSH in low
normal range
Incidental Nodule on U/S
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Most are benign and can be monitored
without further testing
FNA if
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nodule becomes palpable
findings suggestive of malignancy on u/s
larger than 1.5 cm
Hx of head or neck irradiation
Strong family hx of thyroid cancer
Case
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44 y.o. woman, 2 cm nodule palpable
in left lobe of thyroid gland at annual
exam – smooth, non-tender. No
lymphadenopathy
TSH ordered – normal
Thyroid u/s – confirms 2 cm nodule,
solid
FNA - benign
Case
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Repeat U/S at 1 year – nodule now 2.5
cm in size
Repeat FNA – benign
Could consider suppression therapy, or
continue to follow.