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– Bloodwork– Nuclear scans

• Anatomic– Imaging (U/S, CT,

PET/CT)– Needle biopsy

History Details

• Hyperthyroidism– 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

• 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

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)

The other ones

• Riedel’s thyroiditis• 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

Surgery

Malignant5%

Surgery

Suspicious or Atypical20%

Follow if <4cmSurgery if >4cm

Benign75%

Diagnostic

Consider surgery

Nondiagnostic

Rebiopsy

CystRemove fluid

Follow algorithm

Diagnostic

Rebiopsy

Solid

Nondiagnostic

FNA biopsyType Title Here

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