Evaluating Thyroid Disorders

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• Evaluating Thyroid Disorders

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Evaluating Thyroid Disorders ENT for the PA-C

• Andrew Golde MD,CM FRCSC FACS
• Advanced Ear, Nose and Throat Associates
• Atlanta, GA
• February 2011

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Common Thyroid Disorders

• Hyperthyroidism
• Hypothyroidism
• Thyroiditis
• Thyroid nodules/goiter
• Thyroid tumors
• Thyroglossal duct cysts

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Thyroid Evaluation

• History
• Physical exam
• Bloodwork
• Imaging studies
• Tissue analysis

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Thyroid Testing 2

• Functional
• Bloodwork
• Nuclear scans

• Anatomic
• Imaging (U/S, CT, PET/CT)
• Needle biopsy

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History Details

• Hyperthyroidism
• PMA (pretty much anything)
• Feel worse than hypothyroid patients

• Hypothyroidism
• PMA
• Weight gain

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Physical examination of thyroid

• Stand front or back
• Feel laryngeal framework and hyoid
• Have pt swallow or drink
• Size of gland
• Nodule?
• Tender?

Original photograph Mercado
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Thyroid Function Testing

• Imaging
• Radioiodine uptake
• Differentiate among causes of hyperthyroidism
• Graves vs toxic nodule

• Bloodwork
• Total T4 and T3
• Free T4 and T3
• TSH !!!!!!!!!
• TRH stimulation
• Thyroglobulin
• Thyroid antibodies
• TPOAb
• TgAb
• TSHRAb

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TSH testing

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

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Thyroglobulin (Tg)

• Protein backbone of thyroid hormone
• Mostly stored in colloid
• Small amounts of Tg present in blood of all
  people increases 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

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Thyroid-related Antibodies 1

• Anti-thyroglobulin Ab (TgAb)
• Used in thyroid cancer follow-up after
  thyroidectomy
• If TgAb present ---gt cannot use Tg to determine
  recurrence of thyroid ca
• Papillary and follicular ca
• If TgAB absent ---gt Tg very accurate

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Thyroid-related antibodies 2

• Thyroid Peroxidase Ab (TPOAb)
• Most sensitive test for autoimmune thyroid
  disease (75 Graves 90 Hashimotos)
• TSH Receptor Ab (TRAb)
• Cause hyperthyroidism in Graves
• 90 detectable
• Not need to test for most patients

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Radioiodine testing

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

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Suspected hyperthyroidism

• Symptomatic
• TSH normal ---gt not hyperthyroid
• TSH suppressed ---gt assess etiology
• Ex TPOAb, TRAb

• Asymptomatic
• Low TSH in older adults
• Excessive thyroid hormone intake
• Subclinical Graves

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Suspected hypothyroidism

• Symptomatic
• TSH normal ---gt not hypothyroid
• TSH high
• Free T4 low
• TPOAb elevated
• Hashimotos

• Asymptomatic
• High TSH in 3.5 men and 8 women
• 17 women over age 60 have high TSH
• Subclinical Hashimotos

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Thyroiditis

• One of most common endocrine abnormalities
  clinically
• Ex. Hashimotos
• Diverse presentation
• Goiter lt-----gt life-threatening illness
• Hypothyroidism lt-----gt Hyperthyroidism

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Types of Thyroiditis

• Chronic lymphocytic (Hashimotos)
• Subacute (sporadic, postpartum, granulomatous)
• Acute suppurative
• Invasive fibrous (Riedels)

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Hashimotos 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

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Subacute thyroiditis

• Destruction-induced thyroididities
• Abrupt onset thyrotoxicosis (leakage of T4 and
  Tg)
• Thyroid enlarges - painful
• Hypothyroidism ---gt recovery?
• Self-limited
• Treat Sx prn (B-blocker, L-thyroxine)

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The other ones

• Riedels thyroiditis
• Invasive fibrous process
• Least common
• Gland hard as rock
• Biopsy to r/o carcinoma
• Acute suppurative
• Extremely rare
• Life threatening thyrotoxicosis
• Painful mass

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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

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Thyroid Imaging

• Ultrasound
• CT scan of neck
• PET/CT
• Radionuclide scanning

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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

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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

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Thyroid Imaging

• CT scan
• Contrast enhanced
• Assess extracapsular spread, tracheal compression
  and deviation, lymphadenopathy,and retrosternal
  extension
• Rarely CT guided FNA

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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

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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

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Nodules - Risk of Malignancy

• Most nodules are benign - 95
• Age lt20 and age gt70
• Male
• Nodule gt4cm
• Hx of radiation to head and neck
• Multinodular goiter and cysts have same risk of
  malignancy

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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

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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

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Evaluation of Thyroid Nodules

• History and physical
• TSH /- thyroid Abs
• Ultrasound
• FNA
• Nuclear scanning (Hyperthyroid)
• CT if suspect retrosternal extension or
  malignancy

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Evaluation of Suspicious Thyroid Nodule
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Thyroglossal Duct Cyst

• Midline neck mass
• Embryologic remnant of thyroid migration
• Gradual enlargement URTI
• Painless unless infected
• Surgical removal (Sis-Trunk procedure)

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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