Ultrasound of the Thyroid: Significance of Calcifications, Cyst and

Ultrasound of the Thyroid:
Significance of Calcifications,
Cyst and other Potential
Pathologic Findings
Tapan A. Padhya, MD
Professor and Vice Chairman
Director, Division of Head and Neck Oncology
Department of Otolaryngology-Head and Neck Surgery
University of South Florida College of Medicine
Attending Surgeon, Moffitt Cancer Center
February 24, 2014
Introduction: Anatomy of the Thyroid
 1st appears in 3rd week of
gestation
 Highly vascular
endocrine gland
 Situated on top of the
trachea (rings #2-3)
 “Butterfly” shape
Introduction: “Swellings” of the Thyroid Gland
 Thyroiditis
– generalized swelling of the thyroid due to autoimmune inflammation
– Acute, Granulomatous, Hashimoto’s, Reidel’s Struma
 Thyroid Cyst
–
Fluid filled
 Thyroid Nodular Disease
– solitary nodule > solid tissue lump within thyroid
– MNG > structurally and functionally heterogenous thyroid enlargement
– Sporadic nontoxic goiter > non-endemic area
 Goiter
–
large swelling/lump of the thyroid mostly benign but can press on vital
structures like the trachea and esophagus
– Can be associated with Hyperthyroidism (Grave’s disease)
 Thyroid Cancer
– Only diagnosed with needle biopsy or surgical removal
Introduction: Thyroid Cysts
 Thyroid “swellings” filling with fluid rather that
thyroid tissue
 > 96% of thyroid cysts are benign (noncancerous)
Introduction: Thyroid Nodules





1 in 12 young women have a nodule
1 in 40 young men have a nodule
50% of 50 year old > at least one nodule
60% of 60 year old > at least one nodule
70% of 70 year old > at least one nodule
A Tsunami of Thyroid Nodules




Increased use of Ultrasound / CT / MRI / PET
Awareness campaigns: “AACE Neck-Check”
~450,000 biopsies/year in USA, ~10% /year growth
Prevalence of 50,000,000 patients with nodules
A Tsunami of Thyroid Nodules




Increased use of Ultrasound / CT / MRI / PET
Awareness campaigns: “AACE Neck-Check”
~450,000 biopsies/year in USA, ~10% /year growth
Prevalence of 50,000,000 patients with nodules
 Potential for ~1.3M biopsies per year
 ~15% “indeterminate” => ~200,000 diagnostic surgeries
per year
A Deluge of Thyroid Carcinoma
60000
56,400 cases in 2012
Median age: 50 years
Total (N)
50000
Male (N)
New Cases (N)
Female (N)
Lifetime risk: 1/97
Mortality ~5%
~500,000 survivors
40000
30000
20000
Overall risk: 5 – 10%
per nodule
10000
0
1974
1980
1986
1992
Year
1998
2004
2010
SEER Database
Rising incidence is increasing the demand for biopsy
Thyroid Nodule
36 year old woman
No symptoms
Routine Gyn Exam
Solitary nodule,
right lobe of thyroid
 RECOMMENDATION 1
– Measure serum TSH in the initial evaluation of a patient with a
thyroid nodule. If the serum TSH is subnormal, a radionuclide
thyroid scan should be performed using either technetium
99mTc pertechnetate or 123-I. Recommendation rating: A
 RECOMMENDATION 2
– Thyroid sonography should be performed in all patients with
known or suspected thyroid nodules. Recommendation rating: A
Cooper et al. Thyroid 2009;19:1167
Imaging of the Thyroid
 Ultrasound > MOST
COMMON USED
TEST
– Inexpensive
– Cyst vs solid nodule
– Size accuracy > detect
nodules 2-3 mm
 CT imaging
– Assess invasion into
trachea/esophagus
– Assess cervical nodal
disease
Prevalence (USA) of Thyroid Nodules
by Palpation and Ultrasound
70
60
50
Prevalence 40
(%)
30
20
10
0
0
10
20
30
40
50
60
70
Age (years)
Mazzaferri EL: NEJM 328:553, 1993
80
90
Thyroid Nodule - Ultrasound
ATA, NCCN and AACE all support US as initial evaluation
Ultrasound Criteria for Malignancy
Sipos 2009
No microcalcifications
Smooth border
Minimal flow
Wider than tall
Isoechoic
Halo visible
Frates et al Radiology (2005) 237:794-800
Sampling artifact and
nodule selection may
affect test performance
(Cytology and Molecular)
Risk Factors for Thyroid Cancer





Age: > 40 years old
Gender: Male
History of neck irradiation
Family history of Thyroid cancer
Symptoms:
– new onset dysphagia
– New onset hoarseness
 Signs:
– Firm, irregular nodule
– Enlarged lymph nodes in neck
 Radiology:
– Single solitary nodule on ultrasound
– “cold” nodule on Radioactive Thyroid Scan
Introduction: Pathology of Thyroid Cancer
 Malignant Tumors
–
–
–
–
–
–
Papillary carcinoma
Follicular carcinoma
Medullary carcinoma
Anaplastic carcinoma
Lymphoma
Hurthle cell/Insular cell
carcinoma
– Metastasis to thyroid
Bethesda Classification for FNA Cytology
“Indeterminate”
Cibas et al 2009
Bethesda Classification for FNA Cytology
RoM (%)
12
6
16
25
62
97
Cibas et al 2009; Wang et al 2010
Malignancy Risk in FNA Cytology
Wang et al, 2011 – Studies since 2001 – The Ultrasound era
Can the laboratory help us do better?
Bethesda system
Benign
Indeterminate
AUS/FLUS
Neoplasm
Benign
No surgery
Molecular
studies
Malignant Optimal surgery
Suspicious
Malignant
Nondiagnostic
Commercial tests
ATA Guidelines
 Recommendation: Molecular testing can
be considered to more accurately define
nodules that are indeterminate by cytology
 Recommendation strength: C
(majority expert opinion)
Asuragen miRInform™Panel
Applying the “Oncogene Panel” to Indeterminate
FNA Cytology
Positive test: 87% chance of cancer
Nikiforov et al 2011
Negative test: 14% residual risk
46% of samples analyzed; several post-hoc exclusions applied
Afirma™ Negative Predictive Value
Alexander et al, NEJM 2012
Veracyte’s Total Solution for
Thyroid Nodule Evaluation
“A cost-effective, safe ‘rule out’ test to avoid surgery
in up to 50% of patients with indeterminate cytology”
http://www.veracyte.com/afirma/Overview/
Using Oncogene Panel to Influence Surgery
PPV robust; NPV acceptable if ROM<15%
Nikiforov et al 2011
Recommendations for Surgery
for Indeterminate Thyroid Cytology
ATA Guidelines 2009
 Lobectomy
 Completion thyroidectomy if histology proves
positive for malignancy
 Total thyroidectomy for high-risk patient, bilateral
nodules, family history
 Completion surgery needed in ~25%
 Many surgeons use Total-Tx routinely, to avoid the
need for second surgery
Thyroid Nodule - Diagnosis
BRAF / RET-PTC –’ve / RAS positive FV-PTC
Total thyroidectomy at first surgery
National Comprehensive
Cancer Network®
Moffitt Cancer Center
“Endorsed by NCCN Guidelines”
“If molecular testing predicts a risk of malignancy of …
(approximately 5% or less)…..” observe
Special Considerations
1.
Length of Thyroid Nodule Followup
•
Benign nodules with thyroid ultrasound 6-18 months after initial
FNA
•
If still stable (< than 50% change in volume or < 20% increase in at
least two dimensions/2mm) interval can move to every 3-5 years
•
If > 50% change in volume or >20% increase in two dimensions/2
mm then repeat FNA
2.
Cystic Lesions
•
Benign cytology lesions can be removed if compressive symptoms
and/or cosmetic concerns
Special Considerations
3.
Suppression Therapy of Benign nodules cytology
•
4.
Not recommended
Thyroid Nuclear Imaging
•
Only in cases when TSH is subnormal. Otherwise, Thyroid ultrasound is the imaging of
choice.