of thyroid nodules甲状腺结节的评价课件

Evaluation of Thyroid Nodules Eric Oliver August 30, 2007 Objectives nDiscuss Common Causes of Thyroid Nodules nHighlight Application of Imaging Studies in Evaluation of the Thyroid Nodule The Thyroid Nodule nIt is estimated that the prevalence of thyroid nodules in the general population is 4 - 7%. nBenign adenomas or cysts account for approximately 90% of detected thyroid nodules. nIn the U.S., 10,000 to 17,000 new cases of primary thyroid cancer are diagnosed each year. n1,000 - 2,000 people die each year from primary thyroid carcinomas. Causes of Thyroid Nodularity nBenign nFollicular Adenomas nMultinodular goiter (colloid adenoma) nHashimotos thyroiditis nCysts (colloid, simple, hemorrhagic) Causes of Thyroid Nodularity nMalignant nPapillary Carcinoma nFollicular Carcinoma nMedullary Carcinoma nAnaplastic and poorly differentiated carcinoma nPrimary lymphoma of the thyroid nMetastatic carcinoma (especially breast and renal cell carcinoma) Low Suspicion nFamily history of autoimmune disease (eg, Hashimotos thyroiditis) nFamily history of benign thyroid nodule or goiter nPresence of thyroid hormonal dysfunction nPain or tenderness associated with nodule nSoft, smooth, and mobile nodule Hegedus: N Engl J Med, Volume 351(17).October 21, 2004.1764-1771 Case 1 A 16 year old female is seen because of a 6 month history of fatigue, nervousness, tremor, heat intolerance, polyphagia and weight loss. Her scholastic work has declined in quality. Recently she noticed some enlargement of her neck and prominence of her eyes. Physical examination reveals: B.P. 130/60 mm Hg., pulse 96/minute, smooth warm skin, eyelid retraction, symmetric thyroid enlargement, fine hand tremor and mild muscle weakness. Her TSH is low. Low TSH nSuspect independently functioning thyroid n10 percent of patients with a solitary nodule have a suppressed level of serum thyrotropin nNext Step: Scintography Radionuclide Scanning nUsed to identify whether a nodule is functioning. nFunctioning nodules are nearly always benign nApproximately 90 percent of nodules are nonfunctioning n5 percent of nonfunctioning nodules are malignant nThus, in the patient with a suppressed level of serum thyrotropin, radionuclide confirmation of a functioning nodule may obviate the need for biopsy. Scintigraphy nUsually either Technetium or Radioiodine nNormal follicular cells will trap both but only radioiodine is added to tyrosine and stored in the colloid space nBoth benign and almost all malignant neoplastic tissue concentrate both radioisotopes less than normal thyroid tissue n5-8% of warm or cold nodules are malignant Cold Nodules nThyroiditis nFibrosis nCyst nNon-functioning Adenoma nMultinodular Goiter nMalignancy Scintigraphy Hot Nodules nFunctioning Adenoma nThyroiditis nMultinodular goiter Scintigraphy Limitations of Scintigraphy nTwo dimensional scanning technique nInability to measure the size of a nodule accurately nMissed malignant thyroid nodules Case 2 TR is a 40 year old female who presents for her annual physical. On exam, you palpate a 1.5x 2 cm nodule in the right lobe of her thyroid gland. The nodule is non-tender and mobile. Both her TSH and free T4 are normal. What test would you order next? Ultrasonography nFacilitate fine needle aspiration biopsy of a nodule nAssess the comparative size of nodules, lymph nodes, or goiters in patients who are under observation or therapy nEvaluate for recurrence of a thyroid mass after surgery Normal Right Thyroid Lobe Goiter Incidentalomas Fine-Needle Aspiration Biopsy nMost important step in the diagnostic evaluation of thyroid nodules, exception would include hyperthyroidism where scintigraphy should be performed first or highly suspicious exams warranting immediate surgery. nMean sensitivity higher than 80% and specificity higher than 90%. nCan categorize tissue into the following diagnostic categories: malignant, benign, thyroiditis, follicular neoplasm, suspicious, or nondiagnostic nCost Effective some studies estimate that it reduces cost by 25 % and reduce the need for diagnostic thyroidectomy by 20-50%. FNAB Limitations nHypocellular aspirates may be observed in cystic nodules, or they may be related to biopsy technique. nThe absence of malignant cells in an acellular or hypocellular specimen does not exclude malignancy. nInability to reliably distinguish a benign follicular neoplasm from a malignant neoplasm. nAspirates may be required from multiple sites of the nodule to improve sampling. FNAB Ultrasound Guided FNAB FNAB FNAB Case 3 nF.H. is a 66 year old man who complains of a “a bump in his throat.” He states that he has also developed some discomfort while eating more recently. PMH is significant for childhood neck irradiation. There is no palpable mass on exam and oropharynx is clear. Algorithm for the Cost-Effective Evaluation and Treatment of a Clinically Detectable Solitary Thyroid Nodule Hegedus: N Engl J Med, Volume 351(17). October 21, 2004. 1764-1771 Take Home Points nHyperfunctioning nodules (Low TSH, High T3/T4) are almost always benign and biopsy is generally not recommended. Scintigraphy may aid in evaluation and treatment. nConsider FNAB for patients with normal and hypofunctioning nodules. nPatients in which there is a high suspicion can immediately be referred to ENT for surgery. References n/FunctionTests/ultra-frame.htm nFord. Evaluation of Thyroid Nodules. http:/c