Evaluation of Thyroid NodulesMichael L. Tuggy, MDSwedish Family Medicine, Seattle, WA
Case 142 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?
Age as a Risk FactorAge young patients (60 years of age) -higher risk, especially of more aggressive thyroid tumors.
Gender and Thyroid NodulesGender male -higher risk if nodule presentfemaleshave many more nodulesless likely to be malignant.still have majority of thyroid cancers
Other major risksRadiation to head and neck. 40% risk of thyroid cancer usually 25 years later.Exposed populations- Polynesian studiesFamily History of MEN II, Gardners Syndrome, Cowdens disease.
Historical Red FlagsRecent growthSoft tissue swellingVocal changesDysphagiaSigns of thyroid dysfunction
Case 226 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?
Physical Exam of the ThyroidUse both hands simultaneously to evaluate for symmetryPatient upright - screening examPatient supine with neck in extension- detailed exam. Swallowing assists in elevating gland.Evaluation of other neck structures.Voice changes (recurrent laryngeal nerve).
Thyroid ScansPurpose Determine function of the gland and/or a nodule within the glandHot nodules - usually independently functioning nodules Rarely, rarely malignantCold nodules - either adenoma or maligancy15% chance of malignancy in adults.
Thyroid UltrasoundCan identify presence of nodules.May be able to characterize follicular vs. solid.Not able to rule our malignant noduleAid in biopsy.Thyroid
Case 330 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?
Fine-Needle AspirationBest 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.
Interpreting the Biopsy ReportWhat you get:benignindeterminatesuspiciousinadequate specimenWhat it means:benign - 90-95% likelihood it is benignindeterminate- who knows?suspicious- its malignant.inadequate specimen - do it again (and again)
Thyroid Malignancies- PapillaryMost common30% have node metastasis at diagnosisRadiation relatedHistologically, psammoma bodies distinguish from benign adenoma.
Thyroid Malignancies-Follicular20 % of malignanciesDistinguished from normal follicular adenomas by invasion of capsule or blood vessels.May be difficult to determine on FNA
Thyroid Malignancies- Medullary5-10% of casesarise from the C cells which produce calcitonindiagnosis based on elevated thyrocalcitonin levels and thyroid nodule (cold)
Thyroid Malignancies- Anaplastic< 10%Highly aggressive with local extension at time of diagnosis.No suitable therapyPrognosis < 1 yr from diagnosis
TreatmentFor 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.
What about those benign nodules?No specific treatment is needed.Thyroid suppression may shrink size of adenomasNot proven to be effective or necessaryMay hide malignancies - ? Periodic biopsies or scans.
Case 4 - This weeks puzzler!40 y.o. WF s/p I131 ablation for Graves Dz. 6 years ago.Persistant R thyroid nodule 2 x 1.5 cm in size.
What is the likely diagnosis?
OutcomesCase 1. - Papillary cancer - 3 (+) nodesno metastasis at 1 year.Case 2. - Follicular cancer - 5 (+) nodesno metastasis at 1.5 yearsCase 3. - Large adenoma with incidental 1 cm papillary carcinoma superior to nodule.No recurrence at 5 years.Case 4. - Non-functional adenoma
Modified from: Castro, MR, Gharib, H. Endocr Pract 2003; 9:128.
Summary:Solitary Nodule EvaluationTSH 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 biopsylow risk - FNAif indeterminate- scan and re-FNA or excisional biopsy.Anti-perioxidase Antibody helpful if low- TSH to diagnose thyroiditis.
Never assume a solitary thyroid nodule is benign. Prove it.