1. Stanley A. Tan MD, MS, MPH, PhD, DTM&H, FACE, FACC, FCCP
Fayetteville VA Medical Center Grand Rounds January 16, 2015 Fayetteville, NC Thyroid Update
Stanley A. Tan
MD, MS, MPH, PhD, DTM&H, FACE, FACC, FCCP

2. Disclosure Statement
Nothing to disclose

3. Objectives
After this grand rounds presentation, you should be able to:
1. Diagnose and manage hypothyroidism & hyperthyroidism
2. Evaluate and manage thyroid nodule(s) and goiters
3. Describe and manage thyroid cancers

4. Thyroid Anatomy Largest endocrine organ in body—20 g
Right and left lobes
Isthmus
Pyramidal lobe
Goiter = enlargement of thyroid
Diffuse
Nodular

5. Thyroid Physiology Iodide + tyrosine MIT + DIT = T3 2 DIT = T4
Thyroglobulin – storage
Thyroid binding globulin – circulation
Deiodinase
T4  T3

6. Thyroid Physiology Hypothalamic-Pituitary-Thyroid Axis Thyroid C-cell
TRH (stimulates TSH & Prolactin)
TSH
T4 & T3 – Negative feedback
Thyroid C-cell
Calcitonin
Thyroid Medullary Carcinoma (MEN type II)

7. Thyroid Diagnostic Evaluation
TSH
Free T4
Old tests: T4, T3 uptake, FTI
T3—Total & Free T3
Thyroid Peroxidase Antibody
Old test: Anti (thyroid) microsomal antibody
Thyroglobulin Antibody
Thyroglobulin

8. Thyroid Imaging Thyroid Ultrasound Scan RAI Thyroid Uptake & Scan
Anatomical
RAI Thyroid Uptake & Scan
Physiologic & Anatomical
Uptake
High: Graves’, Hashimoto Thyroiditis, Plummer’s
Low: Hypothyroidism, exogenous thyroid or iodine, Subacute Thyroiditis
Scan
Graves—Diffuse
Hashimoto—Diffuse or patchy
Plummer’s—Multi hot nodules
Cold nodule—1-5 % malignancy

9. FNA Thyroid Biopsy Solitary Nodule “Cold” nodule
If negative, observe; repeat ultrasound scan 6 mo, rebiopsy if larger; continue observe if stable
If indeterminate, thyroid suppression; ultrasound 6 mo later, rebiopsy if larger or not shrinking

10. Hypothyroidism Symptoms Signs
Weight gain, tired, sleepy, cold intolerance, constipation
Signs
Myxedema facie, dry skin, scalp hair loss, brittle nail, periorbital edema, decreased DTR
Goiter
Hashimoto thyroiditis, adenomatous
No goiter: Idiopathic Primary Hypothyroidism

11. Hypothyroidism Diagnostic Studies Therapy
TSH, Free T4, Thyroid Peroxidase Antibody
Thyroid Ultrasound Scan
Therapy
Levothyroxine
Dessicated Thyroid
Liothyronine

12. Hyperthyroidism Graves Hashimoto Thyrotoxicosis Plummer’s Disease
Graves opthalmopathy
Goiter
Hyperthyroidism
Thyroid Stimulating Immunoglobulin (TSI)
Hashimoto Thyrotoxicosis
Thyroid Peroxidase Antibody
Plummer’s Disease
Hyperthyroid Multinodular Goiter

13. Hyperthyroidism Subacute Thyroiditis Acute Suppurative Thyroiditis
Painful Goiter
Elevated Sed Rate
Decreased RAI Thyroid Uptake
Acute Suppurative Thyroiditis
Struma Ovarii
Exogenous thyroid
Secondary—TSH producing pituitary tumor

14. Goiter Diffuse Multinodular Solitary Nodule Hashimoto Thyroiditis
Graves’ Disease
Subacute Thyroiditis
Postpartum, Silent, Painless Thyroiditis
Adenomatous Goiter
Multinodular
Plummer’s Disease
Adenomatous Multinodular Goiter
Solitary Nodule

15. Evaluation of Thyroid Nodule
FNA Thyroid Biopsy
Solitary Nodule
Dominant Nodule in a Multinodular Goiter
“Cold” Nodule
If benign, observe, repeat ultrasound scan in 6 mo
If indeterminate, suppress, repeat scan, rebiopsy if not shrinking or enlarging

16. Thyroiditis Hashimoto Thyroiditis Subacute Thyroiditis
Postpartum, Silent, or Painless Thyroiditis
Acute Infectious Thyroiditis
Riedel’s thyroiditis

17. Hashimoto Thyroiditis
Chronic lymphocytic thyroiditis
Associated Polyglandular auto-immune disease (Schmidt’s Syndrome)
Thyroid Peroxidase Antibody
Transient hyperthyroidism (Hashimoto Thyrotoxicosis), euthyroidism, then hypothyroidism

18. Thyroid Cancer Thyroid Papillary Carcinoma
Thyroid Follicular Carcinoma
Thyroid Medullary Carcinoma
Undifferentiated Thyroid Carcinoma
Lymphoma

19. Thyroid Carcinoma Thyroidectomy High dose I-131 radiation therapy
Synthroid suppression
Non-detectable TSH
Yearly Thyroglobulin level
RAI Total Body Scan
Year anniversary
Thyrogen stimulated

20. Thyroid Carcinoma Thyroid Papillary Carcinoma
Local lymph node invasion
Thyroid Follicular Carcinoma
May be mixed with papillary
May be T4 producing—can cause hyperthyroidism with metastases
Hematogenous metastases to bone

21. Thyroid Medullary Carcinoma
Thyroid C-Cells
Calcitonin
MEN Type II
Sipple Syndrome
Pheochromocytoma, Thyroid Medullary Carcinoma, Parathyroid Adenoma
Autosomal Dominant
Surgery