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

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

Thyroid Evaluation History Physical exam Bloodwork Imaging studies Tissue analysis

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

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

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

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

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)

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

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

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

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’

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Evaluation of Suspicious Thyroid Nodule

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

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