Evaluation of Thyroid Nodules

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  • 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?

  • Thyroid Exam

  • 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.