1. Evaluation of Thyroid Nodules
Michael L. Tuggy, MD
Swedish Family Medicine, Seattle, WA

2. Case 1
42 y.o. male with no active medical problems. During your routine physical, note a thyroid nodule. Told by ENT last year not to worry about it.
PE: 1 x 2cm R lower pole nodule.
What information do you want from the patient?

3. Age as a Risk Factor Age young patients (<20 years of age)
thyroid nodules are much more likely to be malignant (40-50%).
elderly (>60 years of age) -higher risk, especially of more aggressive thyroid tumors.

4. Gender and Thyroid Nodules
male -higher risk if nodule present
females
have many more nodules
less likely to be malignant.
still have majority of thyroid cancers

5. Other major risks Radiation to head and neck.
40% risk of thyroid cancer usually 25 years later.
Exposed populations- Polynesian studies
Family History of MEN II, Gardner’s Syndrome, Cowden’s disease.

6. Historical Red Flags Recent growth Soft tissue swelling Vocal changes
Dysphagia
Signs of thyroid dysfunction

7. Case 2
26 y.o. Eritrean female with a 2-3 year history of goiter. No symptoms but noted enlargement on right for 1 year.
P.E.: 3x4 cm Right sided thyroid mass, firm, adherent to soft tissue.
What physical findings are worrisome?
How can you best clarify the nature of the nodule?

8. Thyroid Exam

9. Physical Exam of the Thyroid
Use both hands simultaneously to evaluate for symmetry
Patient upright - screening exam
Patient supine with neck in extension- detailed exam. Swallowing assists in elevating gland.
Evaluation of other neck structures.
Voice changes (recurrent laryngeal nerve).

11. Thyroid Scans
Purpose
Determine function of the gland and/or a nodule within the gland
Hot nodules - usually independently functioning nodules
Rarely, rarely malignant
Cold nodules - either adenoma or maligancy
15% chance of malignancy in adults.

12. Thyroid Ultrasound Can identify presence of nodules.
May be able to characterize follicular vs. solid.
Not able to rule our malignant nodule
Aid in biopsy.
Thyroid

13. Case 3
30 y.o. WF with enlarging cold benign thyroid adenoma (diagnosis from previous FNA biopsy).
PE: 4 x 5 cm mass on Right
What do you do now?

14. Fine-Needle Aspiration
Best tool for determining pathology other than surgical excision.
Can be as high as 80 % sensitive and 95% specific.
Operator dependent in obtaining adequate amount of tissue. 25 gauge needle is optimal.
Should not be relied on if negative in patient with previous neck irradiation.
Multifocal tumors common.

15. Interpreting the Biopsy Report
What you get:
benign
indeterminate
suspicious
inadequate specimen
What it means:
benign % likelihood it is benign
indeterminate- who knows?
suspicious- it’s malignant.
inadequate specimen - do it again (and again)

16. Thyroid Malignancies- Papillary
Most common
30% have node metastasis at diagnosis
Radiation related
Histologically, psammoma bodies distinguish from benign adenoma.

17. Thyroid Malignancies-Follicular
20 % of malignancies
Distinguished from normal follicular adenomas by invasion of capsule or blood vessels.
May be difficult to determine on FNA

18. Thyroid Malignancies- Medullary
5-10% of cases
arise from the C cells which produce calcitonin
diagnosis based on elevated thyrocalcitonin levels and thyroid nodule (cold)

19. Thyroid Malignancies- Anaplastic
< 10%
Highly aggressive with local extension at time of diagnosis.
No suitable therapy
Prognosis < 1 yr from diagnosis

20. Treatment
For all malignancies, excision of the the lobe (or if post-radiation the entire gland).
XRT- very specific and well tolerated- I131 therapy.
Anaplastic tumors - palliative radiation and XRT.

21. What about those benign nodules?
No specific treatment is needed.
Thyroid suppression may shrink size of adenomas
Not proven to be effective or necessary
May hide malignancies - ? Periodic biopsies or scans.

22. Case 4 - This weeks puzzler!
40 y.o. WF s/p I131 ablation for Grave’s Dz. 6 years ago.
Persistant R thyroid nodule 2 x 1.5 cm in size.
What is the likely diagnosis?

23. Outcomes Case 1. - Papillary cancer - 3 (+) nodes
no metastasis at 1 year.
Case Follicular cancer - 5 (+) nodes
no metastasis at 1.5 years
Case Large adenoma with incidental 1 cm papillary carcinoma superior to nodule.
No recurrence at 5 years.
Case Non-functional adenoma

24. Modified from: Castro, MR, Gharib, H. Endocr Pract 2003; 9:128.

25. Summary: Solitary Nodule Evaluation
TSH – if low – scan – if hot nodule, then observe.
Normal TSH - Do I scan first or FNA first?-
high risk - scan and FNA
Is the nodule cold or hot?
Cold - FNA biopsy
low risk - FNA
if indeterminate- scan and re-FNA or excisional biopsy.
Anti-perioxidase Antibody – helpful if low- TSH to diagnose thyroiditis.

27. Never assume a solitary thyroid nodule is benign. Prove it.