1. Evaluating Thyroid Disorders ENT for the PA-C
Andrew Golde MD,CM FRCSC FACS
Advanced Ear, Nose and Throat Associates
Atlanta, GA
February 2011

2. Common Thyroid Disorders
Hyperthyroidism
Hypothyroidism
Thyroiditis
Thyroid nodules/goiter
Thyroid tumors
Thyroglossal duct cysts

3. Thyroid Evaluation History Physical exam Bloodwork Imaging studies
Tissue analysis

4. Thyroid Testing 2 Functional Anatomic Bloodwork Nuclear scans
Imaging (U/S, CT, PET/CT)
Needle biopsy

5. History Details Hyperthyroidism Hypothyroidism
PMA (pretty much anything)
Feel worse than hypothyroid patients
Hypothyroidism
PMA
“Weight gain”

6. Physical examination of thyroid
Stand front or back
Feel laryngeal framework and hyoid
Have pt swallow or drink
Size of gland
Nodule?
Tender?

7. Thyroid Function Testing
Bloodwork
Total T4 and T3
Free T4 and T3
TSH ********* !!!!!!!!!
TRH stimulation
Thyroglobulin
Thyroid antibodies
TPOAb
TgAb
TSHRAb
Imaging
Radioiodine uptake
Differentiate among causes of hyperthyroidism
Graves vs toxic nodule

8. TSH testing Concentration of free T4 genetically determined
Small variations in T4 produce large variations in TSH
-----> TSH is more sensitive test
-----> TSH is only test required to screen patients for thyroid dysfunction
Age related variations (old low; young high)

9. Thyroglobulin (Tg) Protein backbone of thyroid hormone
Mostly stored in colloid
Small amounts of Tg present in blood of all people; increaase with size of gland
Secreted by differentiated thyroid cancers
Major clinical usefulness is in follow-up of patients with thyroid ca after their initial treatment
Tg should be undetectable

10. Thyroid-related antibodies
Thyroid Peroxidase Ab (TPOAb)
Most sensitive test for autoimmune thyroid disease (75% Graves’; 90% Hashimoto’s)
TSH Receptor Ab (TRAb)
Cause hyperthyroidism in Graves’
90% detectable
Not need to test for most patients

11. Radioiodine testing
Useless for determining presence or absence of thyroid cancer
Ex. cold nodule
Used to differentiate among various causes of hyperthyroidism
High uptake ---> Graves’, toxic nodule etc
Low uptake ---> thyroiditis, excessive hormone administration, struma ovarii

12. Suspected hyperthyroidism
Symptomatic
TSH normal ---> not hyperthyroid
TSH suppressed ---> assess etiology
Ex TPOAb, TRAb
Asymptomatic
Low TSH in older adults
Excessive thyroid hormone intake
Subclinical Graves’

13. Suspected hypothyroidism
Symptomatic
TSH normal ---> not hypothyroid
TSH low
Free T4 low
TPOAb elevated
Hashimoto’s
Asymptomatic
Low TSH in 3.5% men and 8% women
Subclinical Hashimoto’s

14. Thyroiditis One of most common endocrine abnormalities clinically
Ex. Hashimoto’s
Diverse presentation
Goiter <-----> life-threatening illness
Hypothyroidism <-----> Hyperthyroidism

15. Types of Thyroiditis Chronic lymphocytic (Hashimoto’s)
Subacute (sporadic, postpartum, granulomatous)
Acute suppurative
Invasive fibrous (Riedel’s)

16. Hashimoto’s thyroiditis
Most common cause of both goiter and hypothyroidism
Most common autoimmune disorder
Painless diffuse goiter; multinodular
Young to middle aged female (30-50)
High titers TPOAb and TgAb
Treatment = L-thyroxine

17. Subacute thyroiditis Destruction-induced thyroididities
Abrupt onset thyrotoxicosis (leakage of T4 and Tg)
Thyroid enlarges - painful
Hypothyroidism ---> recovery?
Self-limited
Treat Sx prn (B-blocker, L-thyroxine)
Sporadic, postpartum, de Quervain’s

18. The other ones Riedel’s thyroiditis Acute suppurative
Invasive fibrous process
Least common
Gland hard as rock
Biopsy to r/o carcinoma
Acute suppurative
Extremely rare
Life threatening thyrotoxicosis
Painful mass

19. Differential Diagnosis of Painful Neck Mass
THYROIDAL
Thyroiditis
Hemorrhage into cyst or nodule
Rapidly enlarging thyroid cancer
NONTHYROIDAL
Infected thyroglossal duct cyst
Infected branchial cleft cyst
Infected cystic hygroma
Cervical adenitis
Cellulitis of neck
Globus hystericus

20. Evaluation of Thyroid Nodules/Goiter
History
Time of onset
Speed of growth
Pain/discomfort
Dysphagia
Hoarseness
Airway compression
Thyroid dysfunction
Family history thyroid disease including ca
Head and neck radiation

21. Evaluation of Thyroid Nodules/Goiter
Physical Exam
Palpation - size, tenderness, tracheal deviation, lymphadenopathy
Laryngoscopy (if available) - vocal fold function
Auscultation of chest - biphasic stridor
Visual inspection - retrosternal

22. Thyroid Imaging Ultrasound CT scan of neck PET/CT
Radionuclide scanning

23. Thyroid Imaging Ultrasound (benefits) Gold standard imaging modality
Always first choice
10-13 Mhz linear array; Doppler
Assess morphology, measure dimensions, nodules, vascularity, lymphadenopathy
U/S guided FNA

24. Thyroid Imaging Ultrasound (negatives)
Incidental nodules discovered in up to 48% of patients - 4% “incidentalomas” malignant
Provides no functional information
Poor predictor of malignancy
Irregular margins
Microcalcifications - papillary ca

25. Thyroid Imaging CT scan Contrast enhanced
Assess extracapsular spread, tracheal compression and deviation, lymphadenopathy,and retrosternal extension
Rarely CT guided FNA

26. Thyroid Imaging Nuclear Uptake Scanning (Scintigraphy)
Tc 99m or radioactive iodine (I123 or I131)
Assess functional status of thyroid nodules
“hot” vs “cold”
Increased risk of malignancy in cold nodule
Determine uptake of hyperthyroid gland when considering I131 ablation
R/O lingual thyroid tissue

27. Thyroid Nodules/Masses
High prevalence on palpation
7% women, 2 % men,
Most not clinically recognized
57% on autopsy
Multiple in 48% diagnoses
Incidental findings on imaging studies
Clinical concern is malignancy
Other symptoms: dysphagia, dyspnea, pain, cosmesis, hyperfunction

28. Evaluation of Thyroid Nodules
History and physical
TSH +/- thyroid Ab’s
Ultrasound
FNA
Nuclear scanning (Hyperthyroid)
CT if suspect retrosternal extension or malignancy

29. Nodules - Risk of Malignancy
Most nodules are benign - 95%
Age <20 and age >70
Male
Nodule >4cm
Hx of radiation to head and neck
Multinodular goiter and cysts have same risk of malignancy

30. Evaluation of Suspicious Thyroid Nodule

31. Thyroglossal Duct Cyst
Midline neck mass
Embryologic remnant of thyroid migration
Gradual enlargement; URTI
Painless unless infected
Surgical removal (Sis-Trunk procedure)

32. Summary TSH for thyroid function
Ultrasound to assess for size, nodules
(U/S guided) FNA to evaluate nodules
CT neck with contrast to evaluate other masses/nodes